Ocz Pc-4000 & A8r-mvp

Hellblazer

Hi there,
As a newb(ish) to OC I'm looking for advice on overclocking - specifically RAM (OCZ PC-4000, 500MHz Platinum - successfully tested at 252MHz - 183 divider), I've been keeping an eye on the various guides to 939 overclocking guides & forums, but have got somewhat stuck...

I can get HTT up to 280, keeping CPU clock out of the equation (8 & 9 X multis - stable w. P95 & memtest, running divider at 183MHz), but once I try dropping to 166, to up the HTT, I have real problems with memtest stability.

I have been keeping within the 1700-2200 LDT\HTT link speed advised, but for some reason I think I'm missing something obvious!

Any suggestions would be cool - need more info let me know what - all BIOS etc, not a problem!

TheLostSwede

Hi there,

I know that board have some issues with 1T so please try 2T first and the following settings to see if the ram is stable at "stock" speeds.

FSB Bus Frequency............................250
LDT/FSB Frequency Ratio.......................800 or 4X
CPU/FSB Frequency Ratio.......................10
PCI eXpress Frequency.........................100

CPU Voltage ..................................1.4V
LDT Voltage ..................................N/A
ChipSet (NF4) Voltage ........................Overvolt enabled
DRAM Voltage .................................2.8
+0.03 if not 3.2V ............................

Memclock (DRAM Frequency) ....................200
1T/2T Timing (Command Per Clock)..............2T
CAS Latency (Tcl).............................3 or 2.5 (test was with 2.5)
RAS# to CAS# delay (Trcd).....................3
Min RAS# active time (Tras)...................6
Row precharge time (Trp)......................2
Row Cycle time (Trc)..........................8
Row refresh cyc time (Trfc)...................24
Row to Row delay (Trrd).......................3
Write recovery time (Twr).....................3
Write to Read delay (Twtr)....................2
Read to Write delay (Trwt)....................2
Refresh Period (Tref).........................7.8us
DRAM Bank Interleave..........................auto

DQS Skew Control..............................auto
DQS Skew Value................................
DRAM Drive Strength...........................Normal
DRAM Data Drive Strength......................auto or not reduced
Max Async Latency.............................7ns
DRAM Response Time............................N/A
Read Preamble Time...........................5.5
IdleCycle Limit...............................16 bios default
Dynamic Counter...............................enabled bios default
R/W Queue Bypass..............................8X
Bypass Max....................................7ns
32 Byte Granularity...........................4 beats

Hellblazer

Hi there MackanzOCZ - I'll give it a go shortly - thanks for the suggestions - I've been away for a while so only just had a chance to catch up - I'll let you know how I get on.....

Cheers

Hellblazer

OK tried as suggested, memtest seems stable...ran for 12 hrs+

FSB Bus Frequency............................250
LDT/FSB Frequency Ratio.......................800 or 4X
CPU/FSB Frequency Ratio.......................10
PCI eXpress Frequency.........................100

CPU Voltage ..................................1.4V
LDT Voltage ..................................N/A
ChipSet (NF4) Voltage ........................Overvolt enabled
DRAM Voltage .................................2.85
+0.03 if not 3.2V ............................

Memclock (DRAM Frequency) ....................200
1T/2T Timing (Command Per Clock)..............2T
CAS Latency (Tcl).............................3
RAS# to CAS# delay (Trcd).....................3
Min RAS# active time (Tras)...................6
Row precharge time (Trp)......................2
Row Cycle time (Trc)..........................8
Row refresh cyc time (Trfc)...................24
Row to Row delay (Trrd).......................3
Write recovery time (Twr).....................???
Write to Read delay (Twtr)....................???
Read to Write delay (Trwt)....................2
Refresh Period (Tref).........................???
DRAM Bank Interleave..........................auto

DQS Skew Control..............................???
DQS Skew Value................................???
DRAM Drive Strength...........................???
DRAM Data Drive Strength......................???
Max Async Latency.............................7ns
DRAM Response Time............................N/A
Read Preamble Time...........................5.5
IdleCycle Limit...............................???
Dynamic Counter...............................???
R/W Queue Bypass..............................???
Bypass Max....................................???
32 Byte Granularity...........................4 beats

I don't appear to have options for those marked ???

Cheers

TheLostSwede

You should have those options as well..you may have to enable them in the bios.

Hellblazer

I definitely can't see them looking under Advanced | Memnory Configuration | Memory Timing Configuration - I can set Memclock Mode (200/183/166 etc), MCT Timing Mode (CAS TRAS, TRP etc), I'd guess where you expect them are under User Config Mode - I only have Read Preamble, Async Latency, and CMD-ADDR
However I've been doing some more testing & having forced these timings, everything does seem more stable, currently the RAM seems good running at 254.54 MHz. I have upgraded the BIOS to 0503 today, and got the CPU at 280 x 10 with HTT dropped to 600 (3x), so definitely looking better...although, I'll drop these back down to test the RAM out a bit more

Hellblazer

I've got to say thanks for your help - forcing the timings has really helped, I've been getting the 3700+ up to 3GHz, completely stable. With that, I'm now happier to start fiddling with the RAM side of things, as I know the processor is running like a little beauty, and I can drop that knowing things look good!

Thanks for your help again!

TheLostSwede

I'm glad it got sorted for you