Can someone explain me following thing:

[ndee]

I just read the Hexus.net review of the Epox 8RDA+ and it shows that if you run the CPU/Memory in 133/133, it's faster then in 133/166. Why is that? Something about latency but I just don't get it 🙂

Thanks.

 

[Jeff7]

Could be a misprint, or it could also have to do something with running asynchronously. I've heard that that can cause a performance hit, but I'm not sure on how big of one, or if the ratio of the two speeds has any bearing - like running something at a 4:7 ratio rather than a 'simpler' 1:2 ratio.

 

[CurtCold]

I may be wrong, but I think it has something to do with the CPU and Memory being running at the same speeds, that makes the performance better. kt400 is slower than 333, cause the Ram is running out of spec?

That's prolly the reason.

 

[xSauronx]

maybe cause the cpu has to play catchup with the ram? i read something about this at THG or sharkys or somethin, try lookin there

 

[CrazySaint]

Yeah, running the memory/CPU out of synch causes higher latencies which counteracts the benefit of the extra mem bandwidth. Btw, AFAIK, the 8RDA+ uses a realtek audio chip instead of the nForce APU.

 

[ndee]

Originally posted by: CrazySaint
Yeah, running the memory/CPU out of synch causes higher latencies which counteracts the benefit of the extra mem bandwidth. Btw, AFAIK, the 8RDA+ uses a realtek audio chip instead of the nForce APU.

The 8RDA+ isn't "Soundstorm" qualified, cuz it doesn't have a SPDIF-out or in, not sure, but it's stated in the hexus.net review. But it does use the nForce APU IIRC.

 

[cmdrdredd]

for AMD CPUs running above 333Mhz Memory is not beneficial because the CPU cannot use that much bandwidth at any one time. With Intel P4 systems the P4 is asking for 400Mhz or 533Mhz of memory bandwidth. Running at DDR400 on a P4 running in a 100Mhz FSB situation (QDR 400) will present a smooth flow of data. Running a 533Mhz CPU on anything less than RDRAM or Dual Channel DDR will not be beneficial because the P4 is going to have to wait for the memory controller to catch up to where the P4 wants to be.

 

[Kingofcomputer]

it's called wait state.
when one thing is slow than another, the faster thing need to add some wait states to stop activity to let the slower thing catching up.