Interesting update in the AMD dualcore saga

Shayne White · Post by **Shayne White** » Sat Mar 25, 2006 3:04 pm

Well, just to see what would happen, I finally borrowed my brother's RME Hammerfall HDSP 9652 that was in his PowerMac G5. I couldn't remotely get MME or MIDI to show up in Windows, but ASIO worked OK. So I ran my testing projects...and found, to my great surprise, that it worked no better than Scope's ASIO -- in fact, in some cases it performed worse!! Here's a breakdown of my results:

-System setup: I played all projects at 2.9ms latency. Sonar 5.01, Scope 4.0, Windows XP SP2. Since the Hammerfall is ADAT only, the Scope software had to be constantly running to provide a D/A converter. I simply switched Sonar between the Hammerfall's ASIO drivers and Scope's. I don't know if Scope running would present a problem, but I don't think so. I have a Scope card, a Pulsar card, and a Powersampler, plus the Hammerfall for testing. The Powersampler shares an IRQ with my video card (moving the card to a different slot didn't fix anything, so that isn't the problem -- and anyway, it isn't the master board). Hammerfall ended up sharing an IRQ with Scope.

-Project A: Many Scope synths loaded, light CPU load - 10% or less average. Hammerfall produced no ticks or pops at all, Scope does only when running dualcore.

-Project B: No Scope devices other than a basic mixer. Medium CPU load - 50-60% average. Some ticks and pops with Scope, MANY ticks and pops with Hammerfall -- almost to the point of crackling. Problem was even more apparent when I would scroll through my Sonar project. Dualcore only, CPU load too high for singlecore without raising latency, which negates comparison.

-Project C: Same basic configuration as Project B. Problem not so severe, but unacceptable playback.

-Project D: My project I use for testing when I'm running many Sonar envelopes at 1.5ms latency. This one is worse with singlecore. 10-20% CPU load, no Scope synths. Clicking problem exactly the same with both Scope and Hammerfall.

The bottom line? I've eliminated almost every suspect that could be causing all these problems. I've reinstalled Windows from scratch, I've changed motherboard/CPU/memory, I've done IRQ troubleshooting, I've played around with PCI latency, I did diagnostic mode to remove almost all services/background programs, including Windows themes and fancy graphics. What's left? The presence of Scope itself? No, no one else has had a problem. The only remaining item is my video card, which has been constantly present in my system since 2002. It's an ATi Radeon 8500 128MB AGP. Hammerfall made it even more obvious that the audio performance grew worse when there was visual movement. I don't have another video card to test, though, and no money to buy another one.

So, anyway, for all I know, Scope is completely compatible with multiprocessing/dualcore/AMD x2/whatever. DON'T PAY ANY ATTENTION TO MY RESULTS ANYMORE!

Shayne

Post by **garyb** » Sat Mar 25, 2006 7:01 pm

good/bad news.....

AndreD · Post by **AndreD** » Mon Mar 27, 2006 12:57 am

Is there a "PCi to AGP Bridge" on your mainboard?!

Shayne White · Post by **Shayne White** » Thu Mar 30, 2006 10:04 am

Of course there is.

Another update: I managed to borrow an nVidia Geforce 4 MX 4000 from my dad. Dualcore at higher latencies seemed to work better, but at low latency (2ms) it didn't really work any better, and still worse than single core, no matter what I put the PCI latency settings to. So I've eliminated the video card as a problem. I'm completely giving up, and I have no clue what's causing my problems. As I said above, don't pay attention to my results anymore.

So -- how many other people can use dualcore at low latency successfully?

Shayne

ScofieldKid · Post by **ScofieldKid** » Sat Apr 08, 2006 5:53 pm

A worthy effort. Thanks for posting all of those results Shayne. Just to concur with what you are saying...

I was looking at my X2 under Windows again recently on a gaming system I have. It's interesting to note that if 1) install Cool n Quiet, 2) apply the Microsoft Hotfix, and 3)set XP Power Options to "Minimal Power Manangement" or "Laptop"... then you can right away use something like the AMD Power Monitor utility to watch the state changes. It was just interesting to me just how drastic the changes are... similar to what you see a Pentium-M does on a laptop.

But my general obvservation was that in a tightly controlled DAW environment, running boutique software, you value stability over everything else. My setup is: A16 Ultra -> PulsarII Zlink + PowerPulsar. I'm trying to pay fairly close attention to how the PCI bus is being loaded. The value of the Scope environment is high enough to me that I prefer to not muck up the system with any other cards or drivers.

So the loss of X2 is not a great loss to me. If I can have a stable system by just paying attention to the architecture, that's enough for me. BTW, as recently as a month or two ago I saw some gaming benchmarks somewhere (probably gamepc.com/labs or hardocp ) where they were also still having problems in certain cases where dual core was in play. So... you are/were not alone brudder!