Are There Memory O/C Problems with the 845G Chipset???

[Jola]

Various memory O/C issues have been raised with certain motherboards, eg P4B533-V, in many threads, but these are too dispersed to get decent commentary on them.

What appears to be certain, is that some good 845E boards (Asus P4B533, P4B533-E, Abit, Epox, etc) can do memory overclocks to +200MHz DDR. In spite of the fact that they don't officially support DDR333, most can (or can be made to) work with 3:4 memory ratios which lets them run memory at very high frequencies.

There have been a lot of reports of problems (many very circumstantial, but nevertheless) with 845G motherboards. And not related to specific brands of memory or specific motherboards. In spite of the fact that they (not officially) support 4:5 memory ratios above 132 MHz.

What are your experiences with 845G motherboards? Has anyone run a 175MHz or 200MHz memory bus on an 845G motherboard?

 

[mike9390]

I have an Abit BG7, 2.26B and 256MB of Samsung DTL series DDR. I can run 160/400 no problem, with 2.5/3/3/6 timings and the core at 1.66v and the ram at 2.8v(2.78 actual). The BG7 undervolts a little, that's why I put the actual voltage in parentheses and why I get 1.66v max(1.45v default X 15%). At 400 with 2/2/2/5 timings my alarm goes off and the computer won't boot. I haven't yet tried any other combination of memory timings at 400. I believe I can lower the core to 1.6v(10% overvolt) and ram voltage to 2.7v(2.68 actual) and get stability at 160/400.

I also think this "crappy" DTL has a little more life in her and will go higher. I have tested my FSB up to 175 but is wasn't stable but 170 felt stable. Using the 3:4 CPU/DRAM ratio is a little tricky, just setting the H/W Strap to "LOW" and the DRAM ratio to "3:4" doesn't work for me. But if I set the DRAM ratio to "By SPD", it detects the memory correctly and you get the same effect. I have ran at 150/400 this way. You may have the set the memory timings to "By SPD" also, i'll have to double check that. The only other thing i'll add is I haven't really tested these speeds extensively, as in running Prime95 all night to test stability. I did run Prime95 for a few hours with no errors at 160/400 with the core at 1.66v and the ram at 2.8.

Everyone get different results even with the same brand board, ram and processor. It's a game of luck sometimes but if you do some research and find out what's working, you greatly increase your odds of having overclocking sucess.

Mike

 

[Jola]

Thanks Mike. Your experience seems to blow the theory that it's a general 845G problem. And raises the question again whether certain motherboards are up to it or not.

I must say, everything I have seen points to Abit as the way to go for decent overclocking. But not everybody wants to go for total USB just yet!

 

[gururu]

I have had a similar experience to Mike9390. My Abit BG7 as well let me tackle DDR400. i845E boards seem to be
as great for overclocking, but from what i've seen, the i845g edges it out at DDR333 and above only because of the more advanced architecture. the asus i845g board is supposed to be a great overclocker. some people claim that it is finicky with certain memory brands.

most people hit DDR400 at 3:4 ratios. the bg7 seems to be capable of supporting this setting... in spades.