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Q. How do I lower the latency on my laptop?

By Sam Inglis

I have been experiencing some big problems with latency whilst trying to use Cubase SX. I would be grateful for any help or advice you can offer me. I'm using a Sony Vaio laptop with a 1.4GHz Intel Celeron M processor, 512MB of RAM, a 60GB hard drive, and a Realtek High Definition Audio sound chip. I've tried reducing the buffer size on this driver and upping the sample rate to 96kHz, with no effect on latency. Could the cause be my hardware?

Carol Robinson

Features Editor Sam Inglis replies: The latency is almost certainly caused by the hardware — most built-in laptop sound chips only have Direct X and MME drivers, and these can suffer latencies of half a second or more. Ideally, you'd be better off with a specialist audio device for music with proper ASIO drivers: upgrading your sound hardware will improve both audio quality and driver performance. Either a PCMCIA or USB device should be OK, or a Firewire one if your computer has a Firewire port. However, you could also investigate third-party ASIO drivers such as ASIO4ALL (www.tippach.net/asio4all) which are designed to work with any hardware. 

Published February 2006

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Q. Will my PC run Garritan Personal Orchestra?

By Sam Inglis

I am very interested in purchasing Garritan Personal Orchestra as reviewed in the October 2004 edition of Sound On Sound. My concern is whether my machine will be up to the task of running it. I have a PC running Windows XP with an AMD processor at 1.47GHz and 768MB of RAM. On the Garritan web site it says that the recommended spec is 1.8GHz, but no minimum spec is provided. However, I notice that the test spec in your review was an IBM Thinkpad T40 with a 1.3GHz Pentium M processor and 768MB of RAM. This leads me to think that my machine should be OK. I just wanted to check I wasn't missing anything — does the Pentium M range of processors have an extra edge over my AMD chip, for example?

Rob Shillito

SOS Reviews Editor Sam Inglis replies: Clock rates can be a useful guide to the performance of different CPUs, but they can also be confusing. Apple have spent much PR effort debunking the so-called 'Megahertz myth', but it's perhaps not so well known that this is applicable to Intel and AMD processors as well. The Pentium M processor does indeed use somewhat different technology from other Pentium CPUs, which enables it to carry out more instructions in each clock cycle. A 1.3GHz Pentium M is, in performance terms, the equivalent of a standard Pentium 4 running at 2.2GHz or thereabouts. See Mark Wherry's article on Centrinos in SOS February 2004 for more details (www.soundonsound.com/sos/feb04/articles/centrinos.htm).

For the last few years, AMD have also been engaged in a marketing campaign designed to show that their CPUs are equivalent to Pentium 4s running at much faster clock speeds. For instance, AMD's Athlon XP 2800+ is supposed to be the equivalent of a 2.8GHz Pentium 4 (hence the 2800+ in the name), even though it is actually clocked at 2.25GHz. Similarly, AMD's Opteron 64-bit processors have relatively low clock speeds but offer performance comparable to the very fastest Pentium 4s.

It sounds as though your computer probably has AMD's 1700+ CPU, which in theory should offer performance comparable to a 1.7GHz Pentium 4, closer to the recommended requirement. Running any piece of software on a machine that barely reaches the recommended spec is never very much fun, and you may find yourself running out of notes before you'd like, or being unable to do much else within your sequencing host, but I would think you would be able to get some use from it on your machine — the recommended spec is to 'get the best out' of the library, not a minimum spec required to use it at all.

Published May 2005

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Korg Kronos Tutorial: Save and load programs and combinations (Including USB disc loading)

Q. Will my audio interface reduce the sound quality of a good external ADAT converter?

By Hugh Robjohns

Many interfaces have ADAT connections that allow you to connect external mic preamps and converters — and as ADAT is a digital format, a cheap interface will not compromise the quality of a more expensive external unit connected to it via ADAT.

I have a fairly cheap and cheerful audio interface that has ADAT ports to allow me to add more inputs and outputs. If I were to use these to hook up a more expensive interface with better mic preamps, will I see an increase in quality, or can the cheap interface’s converters still compromise the sound quality anyway?

SOS Forum post

SOS Technical Editor Hugh Robjohns replies: Assuming you connect a higher-quality device you should see an improvement because you’re not at the mercy of any A-D/D-A conversion! Inside your cheap (or any other) interface, there are a bunch of A-D and D-A converters that convert between digital and analogue signals for the unit’s onboard analogue inputs and outputs. These have nothing to do with the interface’s digital (typically AES, S/PDIF and/or ADAT) inputs and outputs.

The digital signals to and from these converters and all of the digital ports are routed through some form of DSP, which handles the task of data reformatting needed to translate between the computer’s USB / Firewire / Thunderbolt ‘language’ and the ‘language’ required by the interface’s converters and digital ports. Think of it not as ‘conversion’, but as ‘reformatting’ or ‘repackaging’. The digital audio data from the ADAT socket is completely unmolested; it’s just repackaged differently as it is passed on to the computer. It is most definitely not converted to analogue and then re-encoded back to digital!

So, in the scenario you describe, the cheaper audio interface is providing the interface between the incoming ADAT data from the higher-quality device and the cheaper device’s USB or Firewire (or whatever other protocol) connection to your computer. The digital audio from the source remains as digital audio throughout that ‘translation’ process, and the only ‘conversion’ that could potentially be incurred is a sample-rate conversion, if the interface provides that facility — and even that remains entirely within the digital domain. Few interfaces offer that facility anyway, which is why it is important to set the clocking options correctly on the interface and external ADAT source!

Ideally, assuming you’re using the preamps on both your cheap interface and the ADAT-equipped mic preamp box, the cheap audio interface would be set as the clock master, the expensive (external ADAT source) one as the slave, and a synchronising word clock signal taken from the cheap interface’s clock-out port to the expensive interface clock-in. That assumes that the A-Ds and D-As in the cheap interface perform best when running on their internal crystal clock, while the external ADAT source has a decent clock-recovery system. If you’re not using any of the analogue inputs on your cheaper interface and your interface allows, you should set the higher-quality unit as the clock master. 

Published December 2017