DFI RDX200/GSkill PC4800FF overclocking issues

[Cornelious0_0]

Well...this is a bit of a long story, so I'll try and sum it up as best I can...

I've been having some serious issues getting this thing to boot into windows and hold even that amount of stability after a restart. A friend of mine had the same CPU/Mobo/Ram I'm using running at over 300HTT 1:1 at one point...so there's no doubt in my mind that I should be able to achieve what I'm striving for...290x10 1:1, as the CPU benches just fine on it's own (with the memory clocked down).

I've tried so many memory timing combinations my head is starting to spin.

First off, I've been in constant contact with the USA support rep for GSkill, bouncing ideas off of him.

We've come to the conclusion so far that because the previous owner had this stuff running faster then I'm attempting to, and because it boots at 200MHz 2-2-2-5 no problem, chances are that it's simply a BIOS config issue.

The following timings are what the GSkill rep directed me to:

Bios > Genie Bios Setting
FSB = 300
LDT/FSB Frequency = 3
DRAM voltage = ~2.7v

Bios > Genie Bios Setting > DRAM Configuration
MHZ = 200, 1/1
CPC = Enable
Tcl = 2.5
Trd = 4
Tras = 8
Trp = 4
Trc = 8
Trfc = 14
Trrd = 2
Twr = 2
Twtr = 1
Trtw = 2
Tref = 4196
DRAM Bank Interleaving = Enable
DQS Skew Control = Auto
DQS Skew Value = Auto
DRAM Drive Strength = 1 (or best for your computer)
DRAM Data Drive Strength = 2 (or best for your computer)
Max Async Latency = 8ns
Read Preamble Time = 5ns
Idle Cycle Limit = 256
Dynamic Counter = Enable
R/W Queue Bypss = 16x
Bypass Max = 7x
Burst Length = Enable

The timings were listed as a guide for the DFI CFX3200 board, but he also told me that aside from the DDS and DDDS he used all the identical timings with an RDX200 "back in the day" and it worked fine.

Because the guide is written geared towards the memory running at 300MHz I've decided to back down to 300x9 1:1 as my goal as opposed to 290x10 1:1. I've been having slight stability issues at 290x10 on air and this way if I can stablise 300x9 I should be able to just bump the voltage and HTT multi up to jump straight to 3GHz 1:1 when I get h2O on this thing.

But...back on topic. Initially the listed timings did not work for me, and I was told that it's more often then not the DDS and DDDS that need to be worked on. Problem is that I've tried EVERY single combination of DDS and DDDS (all 61 of them) with no luck.

I'm not sure what to look at next...but I am determined to get this working the way I know it can. Hopefully once I get it running at 300x9 I can leave the timings alone and move backwards a step or two on the HTT to 290x10 but we'll see.

If anyone has any suggestions or input as to what to try next I'd be greatly appreciative.

[Cornelious0_0]

Well, 280x10 is the best I can do on air with full Prime stability...so that's where I'm left to work from in terms of memory timings.

280MHz 1:1 3-4-4-8 2T boots with no other settings, but moving to either CAS2.5 or 1T results in the original issue I had where it would not pass the "Verifying DMI Pool Data" point on startup.

I booted again at 3-4-4-8 2T to find out what timings the board was imposing by default to maybe get an idea of where we're starting from. Here's the timings that it's using to boot at 3-4-4-8 2T (everything else at auto):

Tcl: 3
Trcd: 4
Tras: 8
Trp: 4
Trc: 11
Trfc: 14
Trrd: 2
Twr: 3
Twrt: 2
Trwt: 8
Tref: ???
Twcl: 1
Bank Interleaving: Enabled

DQS Skew Control: ???
DQS Skew Value: ???
Drive Strength: ???
Data Drive Strength: ???
Max Async Latency: 8ns
Read Preamble Time: 6ns
Idle Cycle Limit: 16
Dynamic Counter: Enabled
Read/Write Queue Bypass: 8x
Bypass Max: 4x
32Bit Granularity: Disabled

I went back and set everything this way in the BIOS and it does continue to work/boot...but (as you can imagine) performance is dismall.

I'm not sure what the Dram Drive Strength and Dram Data Drive Strength are being set to but "Drive Strength" is listed as "Weak" in A64Tweaker.

Based on the timings above, does anyone have any idea where I might have to start to get it running at 2.5-3-3-6 1T?

[Cornelious0_0]

I realise it's been awhile, but a bit of an update is in order.

For some reason...after folding for more then 2 weeks 24/7 it is now a great deal easier to work with this memory issue.

The system boots and is fully stable at 280x10 1:1 1T 3-4-4-8 without changing any other DRAM options. The system even boots 100% of the time at 2.5-3-3-6...but is unstable...and not able to make it through a run of Aquamark3 without generating memory errors.

This seems to be a little more typical of an issue now, and I was hoping that someone would be able to chime in with some recomendations that'd stablize 2.5-3-3-6, as a number of tests see a good 20+ fps boost (the openning scene of Aquamark3 and Dragothic low detail in 3dmark2001) merely from being able to bench at CAS2.5...and I'd really like to see what kind of scores I'll be looking at in the end.

Any ideas?