Tips & Tricks
Technique : PC MusicianGRAPHICS CARDS & MONITOR SCREENS FOR THE PC MUSICIAN
In the past, PC-based music software was not terribly demanding on the resources used to drive the user's means of visual feedback -- the PC's monitor. But as we try to display more and more MIDI and audio information, via ever more attractive graphic interfaces, your old graphics hardware may not be up to the job. MARTIN WALKER considers your likely requirements.
As we come to expect full waveform displays of our multitrack audio, it is no longer enough to buy the cheapest graphic card and monitor available. Fully-sculpted '3D' screen displays use far more colours than the simple bevelled windows of the past, and if you want to stare at these displays for hours whilst composing your latest masterpiece you will need a large screen with a crisp high-resolution display and lots of colours.
Every PC contains a graphics card, though some have the circuitry incorporated onto the motherboard, and it is this that converts the display information sent by the computer's CPU into video signals that your monitor screen can use. In a sense, it's rather like digital-to-analogue conversion in the audio world.
The current screen image is held in a small amount of very fast RAM on the graphics card, so that it can be accessed very quickly when being converted to the analogue signal. Since increased screen resolution and more colours means that more data must be manipulated, buying a faster graphics card can reduce the strain on your computer's main processor, as it can then deal with this information more quickly. A faster card may also allow the system to update the entire screen display more often, a property measured by the refresh rate. It is normally accepted that to minimise screen 'flicker', the vertical refresh rate (the number of times the screen is redrawn per second)
"If you want to wring out the last drop of system performance, temporarily switching off screen redraws might give you up to 20% more processor time to play with."
should be at least 70-75Hz; some people advise 85Hz. Even if you can't see a flicker at lower rates, it may still cause headaches when viewed long term.
REASONS TO UPGRADE
Despite appearances, the smart new graphic interfaces used by the likes of Ensoniq's Paris, Steinberg's Wavelab and so on are not true 3D -- they merely appear to have depth and solidity due to the way in which the graphics have been drawn. True 3D graphics, and the graphics cards optimised to run them, are used extensively in both CAD (computer-aided design) and by games developers to produce 3-dimensional images that can be rotated, and viewed from a distance or close up. These images are formed by joining together lots of polygons (flat, multi-sided shapes). Plotting the course of these polygons in real time as your objects move requires powerful hardware (and there are other intensive operations to perform simultaneously, such as mapping textures onto the objects' surfaces). If the graphics card contains in its hardware routines to perform these functions, the main PC processor will not have to work so hard.
Most Windows 95 packages, however, including music applications, use only 2D graphics, so there is no point buying a fancy 3D graphics card for these alone. Most modern graphics cards have a combination of 2D and 3D features, and will therefore help with both types of imaging, but if you want the ultimate graphics card for games, you will have to make a different choice. Once again, it is worth pointing out that games and music software don't mix well on the same machine.
SPEED KILLS
As always, PC musicians have a slightly different set of priorities from mainstream computer users. In the never-ending search for 'faster everything', solving problems with the timing of music software comes pretty low in the priorities of graphics card manufacturers. I have already advertised the VGA Kills web site in October's PC Notes, but to briefly recap, many graphic drivers are now optimised by letting them ignore other requests for access to the PCI buss when they are busy plotting graphics. Whilst this makes for fast screen displays that look good in PC magazine tests, it can cause glitches in the audio output, and even spurious swapping of the left and right audio channels with some soundcards. The Zefiro Acoustics web site has the full story (www.zefiro.com).
Thankfully, many graphic card manufacturers now provide software switches that disable this annoying feature. Some solutions involve adding lines of text to initialisation files; another general solution is to lower the Windows Graphic Acceleration by one notch (this can be found in Control Panel, System, Performance, Graphics). However, this may compromise other aspects of graphics performance, and therefore is not really the ideal answer. Problems such as these may leave you wondering whether it's worth the expense of a fast graphics card when you only have to slow its performance down again for audio work. However, most manufacturers tend to perform the same optimisation trick, so a fast card is still likely to be faster than the others even after disabling some of its features.
Most people will already have some sort of PCI graphics card, but if you are still using an ISA buss card then simply upgrading to a PCI card should produce a notable improvement in the speed of screen redraws, particularly when moving between several applications. This is because the buss is responsible for how fast the data reaches the video card, and the PCI buss works faster than ISA. If you already have a PCI graphics card and buy a faster one, you may see only a tiny overall improvement in system performance when running music software, since the average sequencer package, despite its attractive and detailed interface, is still not particularly graphics-intensive.
So why would you need to upgrade or change your PCI graphics card, if the one you have seems to work well enough? Well, many people start off with a 14 or 15-inch monitor screen, and later upgrade to a 17 or 19-inch screen. In order to select a higher resolution that will take advantage of a larger screen, and to get more colours, you may need to add more RAM to your existing graphics card (see the 'Ramming It Home' box for details). Most modern PCs come with 2Mb of RAM on the graphics card (many come with 4Mb) but, if you have an older machine, you may have only 1Mb. At a screen resolution of 1024x768 pixels (the number of dots in each direction), 1Mb of graphics memory will allow only 256 colours. As we shall see, this may cause you problems with the latest software, and upgrading to 2Mb (or 4Mb if this is an option) shouldn't prove too expensive (tens of pounds, rather than hundreds).
Rather than upgrade this RAM, however, you could buy a completely new graphics card; such are the benefits of mass marketing that you can buy a card with 2Mb memory for about £30, and one with 4Mb from about £60. If it would cost £20-30 to expand the memory on your existing card, it might be more sensible to go for a newer and faster card that already has the extra memory. Another benefit of buying all-new hardware is that you may also achieve a much faster refresh rate, which makes the difference between a flickering display updated 60 times a second, and a much less tiring one that updates 80 or more times a second. Let's look at the issues involved in displaying graphics, and try to reach some conclusions about what upgrade options are worth considering.
RAMMING IT HOME
Unless you have a graphics card that can use system RAM to store its images, the amount of RAM installed on the card itself will determine the limits of screen resolution (number of pixels wide by number of pixels high) and bit depth (number of colours). Although nearly all cards come with at least 1Mb already installed, an increasing number now come with 2Mb or 4Mb as standard. If you are thinking of buying a graphics card, you might as well go for 4Mb, as this will meet most most people's requirements with all but the largest 21-inch monitors at photographic quality.
Rather than list the exact memory requirements, the figures below indicate which screen modes will work with the standard 1, 2, 4, or 8Mb sizes.
Resolution 8-bit
(256 colours) 16-bit
(65,536 colours) 24-bit
(16.7 million colours)
640x480 0.5Mb 1Mb 2Mb
800x600 1Mb 2Mb 2Mb
1024x768 1Mb 2Mb 4Mb
1280x1024 2Mb 4Mb 4Mb
1600x1200 2Mb 4Mb 8Mb
1800x1440 4Mb 8Mb 8Mb
À LA MODE
When choosing a graphics mode you set, above all, the screen resolution and bit depth. Resolution determines the size of the desktop, and the bit depth determines the maximum number of colours available to the display. In Control Panel/Display/Appearance, you can change these two parameters (see Figure 1), although you will need to re-boot your PC before you can see the changes. Alternatively, it maybe easier for you to use QuickRes (first mentioned in my very first PC Notes column back in May '97, and available free as part of the Microsoft Power Toys utility), as this allows you to switch modes without re-booting.
The best choice of screen resolution is determined largely by the size of your monitor screen. Although expensive graphics cards may support high resolutions on a small physical screen, you'll find yourself squinting to read some of the text, which breaks the concentration you should be turning to making music. 14-inch monitors seem to have been generally superseded by 15-inch models, and with this size of screen most people recommend using a resolution of 800x600. With a 17-inch monitor, 1024x768 becomes more appropriate, a resolution that can also be used with a 19-inch monitor (though 1280x1024 is also good at this size). For those of you with 21-inch monster screens, either 1280x1024 or 1600x1200 can be used.
The choice of colour (or bit) depth for music applications used to be easy: 256 colours (8-bit) was more than enough in most cases, and even a mere 16-colour (4-bit) screen was quite adequate for some applications. All this has changed, however, with the latest MIDI + Audio sequencers, and their slick graphic design with full display of sample waveforms.
A PAIN IN THE NECK
There's more to getting the most out of your display than resolutions, bit depths and graphics RAM -- physical factors can make staring at a screen a more stressful business than it need be. First of all you should ensure that the display ergonomics are right; that the screen is positioned to create the most comfortable working environment. If you are looking at a screen for long periods, you can minimise the chance of eye strain and headaches by making sure that the top of the visible screen is just below eye level, so that your gaze is aimed slightly downward (this places less of a strain on the muscles controlling the lens in the eye). Try to ensure that the screen is free from reflections and glare. Adjust the screen controls so that the image fills the tube area and does not have a large black border around it -- this will not only give you a larger display, but also reduce the contrast between the edge of the image and the monitor case, which is less tiring.
There should be a distance of at least 16 inches between you and the screen, and preferably between 18 and 30 inches. This can be hard for musicians, since the most suitable place for the monitor screen is often between a pair of nearfield monitor speakers. To maintain a good stereo audio image the screen should not sit forward of the speakers, but this is hard to arrange if you're trying to cater for the typical listening position, with monitor speakers three or four feet apart, and the listener seated roughly this far back from the speakers. A solution popular with many recording studios is to buy a bigger monitor and place it further back, out of the way of the speakers; another is to move the computer and screen to the side of the room, or even along the rear wall, so that you swivel your chair through 180° when working with the sequencer, leaving the screen well away from the speakers.
One source of problems is in the way that 256-colour mode works, especially now that third-party plug-ins can be run within a main application. This mode uses -- no surprise here -- 256 colours taken from the millions available. Thus any application can use a huge range of possible colours, but with the important limitation that it can only ever display a maximum of 256 of these colours available at one time. Each application will have its own palette of 256 colours, appropriate to its visual style.
When reviewing the TC Native Reverb, I noticed that TC Works advise using 65,536 colours (16-bit), particularly when using their product with Steinberg's Wavelab. This is because both the Steinberg and TC Works programs use a significant proportion of their 256-colour palettes, and they have quite different palettes in 256-colour mode. So, when you move from one application to the other, the palette of the 'active' application overrides the previous palette, forcing 'background' applications to use the same palette, a palette which may make them look most peculiar (see Figure 2). In the case of Wavelab and TC Native Reverb, the clash can result in both applications exhibiting permanently flashing colours, a problem that is cured by changing to 16-bit colour depth.
Despite the fact that using 16-bit colour or better will avoid the palette-switching problem, many musicians 'in the know' tend to run sequencers in 256 colours. The reason is that fewer colours used to mean faster screen updates; traditionally, using thousands or even millions of colours offered no visible improvement with most music software, and just slowed your machine down. Nowadays the situation is less clear: most applications use more colours, and to ensure that graphics cards have optimum performance in the most popular graphics mode, manufacturers tend to optimise both their hardware and their drivers for a large number of colours. Because of this, it is quite possible that your PC will run slightly slower when running a particular graphics card in 256 colours than when running in 16-bit colour, simply because few people are expected to use such low colour depths.
Buying a faster graphics card will ensure that screen redraws happen more quickly, and will also probably speed up refresh rates. One reason why fast screen updates are desirable is that they can interrupt overall system performance -- thankfully, most sequencers have intelligent buffering to ensure that updates cause the minimum upset. Screen updates are required constantly; the worst case is when the cursor, scrolling across a waveform, reaches the right-hand side of the screen and the entire display needs updating. I carried out some brief tests to shed more light on the colour depth question, using my new Matrox Mystique 220 graphics card with 4Mb of RAM (my setup, by the way, is a Pentium 166MMX with 32Mb of RAM). The results are very rough and ready, but may be of some use.
Using a screen resolution of 1024x768, I opened Cubase VST, ran the audio demo provided on the Cubase CD-ROM, and monitored the processor usage with Microsoft's System Monitor utility. This comes on the Windows 95 CD-ROM -- if you don't have it installed already, you can do this from the Add/Remove Programs section of Control Panel (in the Accessories section of Windows Setup).
If you use the Line Chart option for Processor Usage in System Monitor, after running Cubase for a few minutes you soon recognise the blip in processor load usage whenever the screen is redrawn because the cursor has reached the right-hand side of the screen (see Figure 3). By way of comparison, I switched off the Follow Song option in Cubase, so that this update would not occur regularly during playback, and found that with the demo song running the average processor load was about in 50% all colour depths. As soon as I switched Follow Song back on, the processor load rose to an average of about 55%, just to plot the moving cursor. When it reached the right-hand side of the screen I measured the following peaks:
With 256 colours (8-bit colour depth), peak load was about 65%.
With 16-bit colour depth, peak load rose to about 70%.
With 24-bit colour depth, peak load rose again to about 75%.
With 32-bit colour depth, peak load was still about 75%.
This suggests that on a typical 166MMX system with a good PCI graphics card, you might expect peak processor overhead to drop by something like 5% if you use only 8-bit colour rather than 16-bit, and by 10% if you drop from 24-bit to 8-bit just for sequencing. However, this peak requirement will occur only once per screen update, so it's not a lot of help overall, and the figures would be different with different graphic card drivers. Nonetheless, if you want to wring out the last drop of system performance, perhaps to give your plug-ins extra room to breath in a critical mastering session, temporarily switching off screen redraws might give you up to 20% more processor time to play with.
GRAPHIC ACCOUNTS
Driver software can cause problems with some applications that use high-resolution graphics, such as the large waveform displays in audio editors. The anonymous PCI graphics card that came with my PC had an annoying habit of corrupting the bottom part of large waveforms with a maximised window within Sound Forge (see Figure 4). Fortunately there is an option in Preferences (Compatible Draw Mode for broken video drivers) which cures the problem. It is not uncommon to trace other odd problems to anonymous graphics cards and their rarely-updated drivers. Another bug that my old card caused was colour corruption in Cubase, whereby the initial screen was drawn with the correct colours, but after scrolling or opening a dialogue box, the updated part of the screen appeared with different colours.
All of these problems disappeared completely when I upgraded to a Matrox Mystique 220 card. After installing it I had a sharper screen display, with more contrast, and I measured a 300% improvement in Windows' graphics speed. As expected, I found that when running Cubase VST both my Event Gina and AWE64 Gold soundcards emitted a click every time the screen was updated. As a temporary solution, simply switching off the Follow Song option removed the clicks, since the screen was no longer being redrawn. However, I eventually discovered that the Cubase problem could be fixed by unticking the Use Device Bitmaps Caching graphics option, which had a minimal effect on graphics speed. Dragging a small window still produced the clicks, which suggested that I might still experience problems at times, but these too were removed when I set Use Automatic PCI Buss Retries to Off (see Figure 5). Steinberg also recommend unclicking the Use Buss Mastering option -- at first I didn't have any problems with this still ticked, but after VST audio recording stopped unexpectedly several times, unticking it seemed to cure the problem. Overall, the combined changes degraded the graphics performance by about 10% -- but that still but left me 290% better off than my previous graphics card...
CHOICES FOR MUSIC
For music applications, a graphics card needs to give a notable improvement when running Windows 95 applications, not when running games soft
"For music applications, avoid anonymous graphic cards, since their drivers may not have the options required to prevent audio glitches."
ware. Motherboards with built-in graphics capability are popular in some quarters, because they avoid the necessity of installing another PCI card, but their performance is not likely to be particularly good, and they can sometimes be difficult to disable when you want to upgrade to a more powerful stand-alone card.
Another recent trend is to cut costs by using system RAM for video, rather than having separate RAM (of whatever description) on the graphics card itself. Again, this at first seems an attractive proposition, because you never need to upgrade your graphics memory -- you simply use more of your system RAM if you want a higher resolution screen. The problem, once again, is compromised performance, because system RAM is not as fast as the various types of dedicated graphics RAM. You may see these specialist types of RAM, all of which can shift video data at high speed, referred to as VRAM (Video RAM), WRAM (used only by Matrox cards), and SGRAM (a special graphics version of SDRAM).
Personally, I chose a Matrox Mystique 220 card (around £80 with 4Mb of graphics RAM, expandable to 8Mb), a card which is regularly quoted as being good value for general-purpose 2D or 3D use. With 4Mb of graphics RAM already fitted, this will support 1280x1024 resolution at 24-bit colour. Although there are known problems with Matrox drivers (see 'Screen Problems') these are easily dealt with by changing a couple of well-known settings.
I've noticed many mentions of the S3 Trio chipset, and the S3 Virge/DX, in systems advertised specifically for musicians in the pages of SOS. There are many such cards around that use the S3 chip, and these can be used with no problems by musicians, once again with the help of a well-publicised tweak (see the 'Other Opinions' box). But, before anyone does it for me, I should point out that there are probably plenty of keenly priced alternative cards out there that will work far better with 3D games; just remember that they may not work so well with sequencer applications.
If you are lucky enough to have one of the Pentium II systems featuring the AGP (Accelerated Graphics Port -- see January's PC Musician feature for more details), then it seems that there may be a hidden benefit in using an AGP graphics card rather than a PCI one. Although AGP has a higher bandwidth, and ultimately will prove considerably faster than PCI, no-one will really notice until Windows 98 appears, as not all of its benefits can be used by Windows 95. Using an AGP graphics card will currently offer only a small improvement in graphics speed. However, if you use an AGP graphics card then graphics data will no longer share the PCI buss with audio data, which means that audio glitches due to badly written graphics card drivers should be a thing of the past. Only two months ago I reported that the AGP buss showed little relevance to musicians from the graphics point of view -- it's ironic that in fact it offers a way to cure an audio problem rather than improving the graphics performance.
OTHER OPINIONS
Some companies that specialise in supplying complete PC music systems use lower-cost generic cards, going against the advice I've set out here -- but they can test a selection of cards and then buy a batch once any problems that arise have been cured. (Individual purchasers rarely have the luxury of buying hardware for a trial run, so it is best to stick to reputable manufacturers whose driver tweaks are well known.) RKMS of Nottingham prefer to specify cheaper cards that have been tested in this way, and recommended two in particular. The Cirrus Logic 5446 64-bit (available in 1Mb and 2Mb versions) normally behaves well once the Windows 95 acceleration is turned down to 'none', and the S3 Virge DX card (available in 2Mb and 4Mb versions) apparently works particularly well as long as you add "busthrottle=1" to the [display] section of your System.ini file.
The Red Submarine Computer Company, suppliers of PC hard disk recording systems who are also happy to sell graphics cards separately, take a slightly different tack in recommending the ATI Expert@Work range, which use the AGP buss. However, for high-end systems employing Pentium II processors, and also for a few very recent TX chipset motherboards, a card using this buss is recommended (see main text for more details). Remember that both these companies specialise in putting together complete hard disk recording systems so, unlike a mainstream computer outlet, they know the potential graphic/audio conflicts. It bears repeating that the best way to avoid problems is to buy a complete system from a specialist, or at the very least to keep your PC a games-free zone to minimise the problems.
MONITOR SCREENS
There is no point in buying a monitor that can be refreshed at 85Hz if your graphics card is only fast enough to drive it at 65Hz. Conversely, simply having a fast graphics card does not automatically let you use the highest available settings for screen resolution and colour depth -- your monitor screen must be able to keep up with the amount of video data being squirted down the monitor cable. Since fast graphics cards are far cheaper than good monitors, many people find themselves able to select a screen mode that sends data faster than the monitor can deal with it. The result is a picture that rolls all over the place, like a TV set with incorrectly set vertical or horizontal hold.
If this happens you'll have an interesting problem -- you won't be able to see to select a different mode to achieve a stable screen again. The solution is to reboot your PC, press the F8 key to bring up the startup menu, and select Safe Mode. This always uses the standard 640x480 16-colour Microsoft driver that is guaranteed to work with any graphics card and monitor, and from here you can select a more suitable screen mode to take effect when you next boot your PC. Many graphics cards also have utilities that allow you to change screen mode, and preview the new display for several seconds before confirming the change; if you don't, they revert to the previous settings, which means that you can recover from screen roll automatically. Remember, however, that even if your monitor prevents you using some of the higher resolutions supported by a faster card, you still get the benefit of faster refresh rates (for less screen flicker) even when running at exactly the same resolution as before.
The reverse situation -- an expensive monitor with a slow graphics card -- will limit the maximum resolution that can be comfortably viewed. The optimum solution is to have a graphics card and monitor screen that are reasonably matched in performance terms. For instance, when I last upgraded my PC, I initially retained my 14-inch monitor to keep the total cost down, which meant it couldn't match the faster refresh rates of my new graphics card; I had to be careful to avoid screen roll when selecting different screen resolutions. On the other hand, after finally upgrading the monitor to a Iiyama Vision Master 17, I could manage only 1024x768 resolution with 256 colours, because the new graphics card had only 1Mb screen RAM. The answer was more RAM for the card (see the 'Ramming It Home' box for details on the amount of RAM required for each screen mode).
The sharpness of the monitor picture is largely determined by the dot pitch (the physical distance between each on-screen pixel), as this determines how many pixels can be distinguished both horizontally and vertically. The finer the dot pitch, the sharper the image. For a 15-inch monitor a dot pitch of 0.28mm should be fine, but for a 17-inch monitor you should be looking for a dot pitch of 0.26mm or less -- many are now available at a sharper 0.25mm, although they may be more expensive.
THE FINAL CHOICE
For music applications, avoid anonymous graphic cards, since their drivers may not have the options required to prevent audio glitches. Stick to well-known makes, and bear in mind that if you buy from a PC music specialist you should have the benefit of a pre-tested range of models -- and of staff who understand specific audio problems. If you are on the internet, take a look at the excellent 'reading room' provided by Mission (www.missionrec.com), and carry out a search for information on any graphics card you are interested in -- you may come across useful comments from other people already using this model in a music environment.
When choosing a monitor, picture quality is the most important factor, and you tend to get what you pay for. That said, Iiyama have a good reputation for quality without the price, and I've certainly been very pleased with the Iiyama Vision Master 17 that I bought some months ago (although the Vision Master Pro range gives even sharper picture quality at a slightly higher price). If possible, take a look at the monitor you intend buying before you take the plunge, and if you intend to buy blind through mail order then make sure you stick to well-known manufacturers.
Published in SOS July 1998
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