Dual Channel Overclocking Woes

[viccyran]

Hey guys, I've been reading this forum for about a month, and I want to thank all the knowledgable people out there that basically got me from nub to semi-nub in OCing.

I have a problem, I searched the OC forum, and saw nothing so here's my post

So yeah, my setup is:
Abit AI-7 latest BIOS revision
2.4c m0 stepping (at 1.6v)
Koolance EXOS
2x512 HyperX DDR500 (at 2.8v)
eeh.. and the rest is nub.

Anyway, at 3:2 with one ram piece, I can push the FSB to 284 before it starts to lock up, and for some odd reason it wouldn't run at 5:4.. I ignored that and just ran it at lower latencies (hyperx is rated at 3-4-4-8, I was running it at 2-3-3-5).

Once I got my other piece, I ran it in dual channel, and now I can't run the FSB past 260, regardless of the memory divider settings. I'm running it at 1:1 260 FSB, and that seems to run rock solid.. but I kind of wanted to push the FSB higher.

I can run the memory at the same time non-dual, and I can push it, but as soon as it goes dual that problem comes up

Which would probably yield the best results? Am I set with 260 1:1? Or should I go for higher FSB. Thanks for reading guys, TIA

 

[unhappy_mage]

260 isn't bad. i'm running a dfi board with a 2.4c, and I can only hit 250 with a 5:4 divider in dual channel. I have older ram (corsair 3200LL) but I bought expensive hoping that would futureproof me. oh well. i'd stick with 260 1:1 unless you can raise the timings a bit and get a better oc. ice czar would be the authority on this, but I seem to recall that having that last number (2-5-5-X) set too low can cause data corruption on your hard drive . also, a test was done with ram at low latency vs. high latency, and the difference was like 2%. I'd go for the high latencies and no data corruption.

 

[gclg2000]

i got a m0 2.4c and mine runs at 275 1:1 with PC4000, i can go up to 284 in dual channel with 5:4.....sounds like your ram isnt liking anything past 260 in dual channel. i think your gonna just have to accept that, it is weird that it only went to 260 though on 2.8v. Try soem new ram or i would just leave it at 260 1:1, i really dont see that much difference anyways from 260 1:1 to 275 1:1

 

[Ice Czar]

from Corruption 101

from Eight Ways To Kill Your HDD

TRAS Violation: The Creeping Corruption of a HDD

One of the most common reasons for HDD failure is what is called tRAS violation. tRAS is the minimum bank open time of the DRAM, that is, we are talking about system memory here. Many mainboard manufacturer still include Ultra and Turbo settings in their CMOS setup options that are only workable at 100 MHz memory bus settings, a.k.a PC1600 mode. One setting that has absolutely no impact on performance is the minimum bank open time or tRAS, while the same setting can have catastrophic consequences for data integrity including HDD addressing schemes if the latency is set too short. In theory, tRAS can be as short as tRCD + CAS delay, however, in reality, the minimum bank open time is dictated by the RAS Pulse Width, that is the time required to reach a voltage differential between memory bitlines and reference lines to safely identify a 0 or 1 logical state.

The main reason why tRAS violation does commonly lead to HDD corruption may relate to the translation of the physical memory space into virtual memory sub-spaces by the operating system and finally writing the data back to the storage media but it is not entirely clear what is going on there. A fact is, though, that a tRAS value of 5 is adequate for PC1600 or 100 MHz operation. At 133 Mz or PC2100, tRAS should never undercut 6T, likewise, at PC2700, the value should be increased to 7T where applicable. In terms of performance, tRAS settings hardly make any difference. We challenged some performance gurus at AMD on this matter and they reported a drop in Quake frame rates from 792 fps to 790 fps when increasing tRAS from 5T to 6T.

for indepth information > tRAS violation as a cause of data corruption @ Lost Circuits