Corsair XMS512-C2 Problems on Abit NF7

[Nikushorul]

Hello.
1 year ago i bought one stick (512M) of Corsair XMS C2 (rev 4.2) for my Abit NF7 2.0, and it works perfectly at 400 mhz with 2-3-3-6 timings, and up to 460 mhz with 2.5-3-3-6 (maybe higher but i'm hitting the fsb limit).

A couple of weeks ago i thought 'time for 1GB, dual channel' and went to the store and came back with another (identical?) stick. Not quite identical, as it shows rev 5.2. After turning on my system, the stability was horrible so i decided to test the new stick alone... It doesn't work at CAS2 / 400 mhz, tried from 2.6 to 2.9 volts (all the settings allowed by my board); it doesn't work at CAS2.5 / 400 mhz regardless of the voltage (going above 2.7 makes things worse it seems). Only works at 400 mhz with 3-3-3-6 timings (actually i've set tRAS to 11 as my board performs best with this setting) and ONLY at 2.7 volts, anything lower or higher gives me errors after minutes/hours of Prime95. Also, i cannot get past 420 mhz even with these crappy timings...

Obviously i'm very disappointed of the new Corsair stick (cost me 90$, and i could have bought no-name ram for half that price and have it perform better), and i'll try to return it next week... But i'm wondering what could be causing that behaviour? Incompatibility between the new revision (i heard it uses ProMos chips instead of Samsung chips used by the older revisions) and my mobo? What else should i try? Test the problem stick on other motherboards? Try a modded bios for my MB? Thanks in advance for any advice you may be having for me! (and excuse my English - it is not my native language).

[Lastviking]

Hello.
1 year ago i bought one stick (512M) of Corsair XMS C2 (rev 4.2) for my Abit NF7 2.0, and it works perfectly at 400 mhz with 2-3-3-6 timings, and up to 460 mhz with 2.5-3-3-6 (maybe higher but i'm hitting the fsb limit).

A couple of weeks ago i thought 'time for 1GB, dual channel' and went to the store and came back with another (identical?) stick. Not quite identical, as it shows rev 5.2. After turning on my system, the stability was horrible so i decided to test the new stick alone... It doesn't work at CAS2 / 400 mhz, tried from 2.6 to 2.9 volts (all the settings allowed by my board); it doesn't work at CAS2.5 / 400 mhz regardless of the voltage (going above 2.7 makes things worse it seems). Only works at 400 mhz with 3-3-3-6 timings (actually i've set tRAS to 11 as my board performs best with this setting) and ONLY at 2.7 volts, anything lower or higher gives me errors after minutes/hours of Prime95. Also, i cannot get past 420 mhz even with these crappy timings...

Obviously i'm very disappointed of the new Corsair stick (cost me 90$, and i could have bought no-name ram for half that price and have it perform better), and i'll try to return it next week... But i'm wondering what could be causing that behaviour? Incompatibility between the new revision (i heard it uses ProMos chips instead of Samsung chips used by the older revisions) and my mobo? What else should i try? Test the problem stick on other motherboards? Try a modded bios for my MB? Thanks in advance for any advice you may be having for me! (and excuse my English - it is not my native language).

Search for a bios with Cpc:disabled , nf2 boards dont like 2x512 and cpc: enabled

[Nikushorul]

Thanks. As i mentioned, the new dimm performs very bad also when tested alone, so i'm not very sure that cpc:disabled would help very much. I am however willing to try such a modded bios if someone reccomends me a bios that has this option, and will work on my NF7 v2.0 (without the risk of killing it).

[chew*]

I think you might find that Corsair uses lots of different chips for the same models of ram. They have an identifier that works byt part# revision # and batch # just because its the same model doesnt mean one chip isnt TCCx and the othe mosel or infineon or whatever. That may be where your problem lies.