Overclocking OCZ PC2-8500 on Abit I-N73HD (nV 630i)

[Sumanji]

Hey,

I'm having a little problem with my OCZ PC2-8500 SLI ready RAM (2GB kit). I am trying to get it to run at rated speed on an Abit I-N73HD motherboard (nForce 630i chipset). This board only officially supports DDR2-800, but it has a wide range of OC options in the BIOS.

Whenever I set the DDR2 speed, voltage and timings to stock (for the RAM) the PC does not boot I have also tried upping VTT and NB voltage to no effect. What else do I need to do? There are other options in the BIOS for voltage (DDR2 REF voltage, CPU GTLREF voltage) and also for memory timing (tRRD, tRC, tWR, tWTR, tREF).

Any help appreciated!

Cheers,

Suman

[Don_Dan]

Do you have the latest BIOS?

Which values did you choose for NB voltage and VTT?
Is your system overclocked besides trying to get the memory to run at 533MHz?

[Sumanji]

Hi Dan,

I've tried the latest BIOS on the Abit website and also a Beta BIOS which tech support sent me. I have tried VTT up to 1.31V (maximum in the BIOS) and NB voltage up to 1.53V (maximum is 1.87V, but the chipset is only passively cooled). Everything else is at stock at the moment...

Cheers,

Suman

[Sumanji]

Ok I've done some more in-depth testing tonight... I've set VDDR to 2.2V, timings manually set to 5-5-5-15-2T. All other voltages STOCK (VTT 1.10V), CPU stock speed. Memory set to UNLINKED.

DDR-800, VMCH 1.36, OK
...
DDR-900, VMCH 1.36, OK
DDR-914, VMCH 1.36, OK
DDR-933, VMCH 1.36, OK
DDR-960, up to 1.67 VMCH, FAIL

Seems even in Unlinked mode the board is using some sort of divider, as I can only increase the Memory speed in the steps which I have listed... so seems there is some sort of ceiling at 933MHz.

I will try increasing VTT etc. and report back!

Cheers,

Suman

[Don_Dan]

Hi!

1.36V NB voltage "should" be enough for DDR2-1066, but don't use unlinked mode, as the chipset is indeed using dividers to generate RAM speed, and some of these dividers are a bit shaky. Well you can in fact use some of the dividers that are known to be stable which you cannot get through linked mode, these are, at least for me, 2:3, 5:6, 9:10 or 9:11. I recommend you use the 2:3 divider and set FSB speed according to the desired RAM speed.

355 FSB -> 533 MHz RAM speed
FSB1421 -> DDR2-1066

Try if you can get 533MHz that way and report back!

[Sumanji]

Hi Dan,

I forgot to mention earlier that Linked mode does not work at all I have the options Auto, 2:1, 3:2, 5:4 and Sync in Linked mode, but all of these fail to post!! So I am forced to run stock "Default" settings, or Unlinked mode... I'm beginning to think maybe the chipset is just unable to cope with fast RAM...

I left Memtest running overnight with these settings:

CPU 12.5 x 266 (3.33GHz) 1.3V, VTT 1.2V
RAM unlinked at 933MHz, 5-4-4-12-22-2T, 2.1V
VMCH 1.40V

It was error free for 7 hours, so now I am running Orthos in Windows to see if it is stable... not bad for such low voltages!

[edit] Small FFT stable for one hour, so I will now run blend until the evening... wish me luck! Note, it initially failed Orthos small FFT in 2 minutes with VCore 1.25V and VTT 1.10V. Seems more stable now

Cheers,

Suman

[Don_Dan]

Yeah, voltages are really low for these settings!

What I tried to say is that there are some dividers in unlinked mode that do actually work. For me setting FSB and RAM speed so I get the 2:3 divider has always worked. Try to use the settings I posted earlier, but lower your CPU's multiplier so your CPU speed is within the speed you're now using and know it's stable ( so multi 9 or maybe 9,5 ). I'd like to know if these settings will work for you and give you DDR2-1066.

[18 is # 1]

You might try asking here: http://forum.uabit.com/index.php?

[Sumanji]

Don Dan, I tried a variety of high FSB's with negative dividers (both Linked and Unlinked) and none of them work tried really really slack timings, lots of voltage etc etc. I think maybe the memory controller is just carp...

Yes, I will try asking in Abit forums as a last resort!

[Don_Dan]

Did you ask at Abit's forums? Were they able to help you?

Just read some specs of the 630i, do you use integrated graphics?