Last weekend, it was finally time for an upgrade to my 1 1/2 years old gaming rig. Amongst other things, I switched from an Asus A8N-E (NForce 4 Ultra) board to an Asus Crosshair (NForce 590 SLI).
This alone solved a lot of issues I was having with my PC. It appears that the NForce 4 chipset has serious problems with heavy bus traffic. If, for example, you’re copying a large file, NForce 4 may fail to deliver the next chunk of audio data to your sound card in time and you’ll hear skips or ugly scratches whilst listening to music.
You can find several references to this bus priorization issue of you google for NForce 4 bus issues. For example:
NForce4 on Wikipedia
Issues With nForce4 Mobo and X-FI Cards
X-FI + Nforce4 = Pops/Hicks/Hisses
The important parts:
We have observed through direct observation of the PCI bus on the nVidia nForce 4 motherboards that when the crackle symptoms are occuring, the Soundblaster X-Fi card PCI bus master memory requests for audio data are being held off (not serviced) for very long intervals.
We have observed peak holdoffs of up to 2 milliseconds in some cases. This is unusual chipset behavior that is beyond the ability of a hardware audio accelerator to compensate for in its internal buffering. The SoundBlaster X-Fi tolerance for these PCI holdoffs is approximately 120 microseconds peak holdoff, with a 1 microsecond average holdoff.
and
Further to the reported cases of crackling issues reported by owners of Sound Blaster X-Fi cards, we have extensively tested both Creative and non-Creative audio cards on motherboards where the issues were reported in an effort to isolate the root cause.
The findings indicate that circumstances causing these audio glitches only arise on Nvidias nForce 4 range of motherboards, with the exception of the newest n590 board which does not exhibit this issue.
The Sound Blaster X-Fi card was designed to meet PCI bus standards and tolerances and this is the only range of motherboards that operate in this manner.
Here’s a list of issues I attribute to the NForce 4 chipset:
- Games that load data in the background momentarily skip a frame or two. As an up to date example, NForce 4 owners playing Need for Speed: Pro Street will experience the game making tiny little pauses while they drive around the track. Enough to completely destroy every sense of speed and to skip past the exact moment you need to turn into a bend.
- You can either watch a movie or defragment your hard drive, but not both. If you try to listen to music or watch a movie during hard drive defragmentation, the sound will hang, skip or scratch every few seconds.
- Your mouse cursor becomes jumpy or temporarily unmovable when you copy large files. As in all the other points, whenever heavy disk activity hogs the system bus, something goes wrong. In this case, the USB devices seem to not be polled in a timely manner anymore.
- Cutscenes played by games while at the same time loading data will hang, jump and have sound distortions. NForce 4 owners playing Call of Duty 4, for example, will have serious trouble understanding the mission briefings played while a level loads. Slower drives might merely destroy the game’s atmosphere.
Now I’ve got the NForce 590 SLI chipset. All of my issues went away with the upgrade:
- The loading screen in Supreme Commander rotates slick and fluid.
- The cutscenes in Call of Duty 4 are intelligible.
- Need for Speed: Pro Street gives me a sense of speed.
- I can watch a movie when I defragment my drive.
- I can use my mouse while I copy large files.
I’ve never been so happy about an upgrade. All of the little issues I was having — gone in an instant.
There are users reporting the issue with the NForce 590 SLI, but all of them have two graphics cards installed and are only experiencing this during heavy usage (eg. 3DMark). I don’t plan on using SLI anyway (I just wanted to get the Asus “Crosshair” :p), so even if the issue is only gone because bus throughput has been dramatically increased, I’m happy 
Recent Comments