April 01 2005:

Welcome Back!

The Bleeding Edge of Technology that we have covered over the last 6 months is now starting to break thru to the mainstream with PCI Express and 64 Bit Operating systems starting to gain momentum. While all looks promising on the surface, those of us who are constantly pushing the envelope are always the hapless fools who are at the most danger of doing ourselves an injury. LOL. While I have been developing my latest 64bit/PCIe DAW systems I have encountered a few unforeseen obstacles that the newer technologies have thrown into the mix.

The first obstacle that was hit was with the newer PCI Express based systems. Despite the promises of the huge bandwidth improvements that PCIe would bring to the table, in reality a lot of systems were displaying alarming performance issues when using any professional Audio Applications. I/O bandwidth problems were being suffered at minimal system loading with symptoms ranging from greatly increased CPU loads compared to similar AGP based systems, to clicks pops and other audio anomalies at far higher latencies. This was in complete contrast as to what we expected. So what’s going on?

In summary the PCIe spec is the direct replacement to the older PCI spec that we have had for quite a while. It is a serial point to point interface where each device sits on its own bus with its own dedicated bandwidth, unlike the previous system where all of the devices would need to share the available bandwidth. Well that’s the theory anyway. Unfortunately while the main focus has been to maintain full backwards compatibility with the earlier PCI spec, there has been varying methods of how the new PCIe spec has been implemented. The problems being experienced are a combination of the miss-mash of PCI -PCIe and PCIe-AGP bridges that are being employed in this transitionary period so that the actual transition is "smoother" for the majority of the industry. This unfortunately has resulted in crippling the performance on numerous combinations of PCIe equipped audio systems.

With Pro Audio being only a minute focus for the MB manufacturers, their main focus is of course the enthusiast/gaming/ corporate market, and in that respect the audio problems being caused by the early implementation of the PCIe spec on these current boards, is of no great concern to them. The early issues of the Intel PCIe systems suffering bandwidth problems, although valid for the various combinations that were initially tested, thankfully proved a little pre-mature, as the solution was found with the correct balance of MB/PCIe graphics. However the AMD-NForce 4 PCIe systems are proving to be far worse, and the olive branch that was discovered for the Intel systems is not holding true for the AMD Camp. Unless a solution can be found, the AMD Audio fraternity may find that they are without a single CPU solution in the very near future. Verdict is still out on the new Opteron Dual CPU systems.