E6850 + Asus P5N32E-SLI Plus, what OC should I try for?

[miteethor]

I have all of my components in:

Intel Core2 Duo E6850, stock 9 x 333
G.Skill 2x1GB DDR2-800 CAS4 F2-6400PHU2-2GBHZ
ASUS P5N32E-SLI Plus MB
Tuniq 120 Air cooler with the blue lighted fan
2xeVGA 8800GT SSC factory clocked at 700MHz in SLI

Now that I have everything hooked up at stock, I want to know what a reasonable overclock would be for this setup. So far the best I've been able to get is FSB @ 366 for a total speed of 3300 on the processor. Every time I try FSB @ 400 I can't even get it to POST.

I noticed that the "AUTO" setting puts my voltage at 1.45 on the CPU, although I've been able to tone that down a bit and I've been stable at 1.30 running with 366 FSB. My memory is unlinked at the moment but I think that the stuff I bought should be able to link?

I want to push this system without going crazy on voltages/heat that will push it out of operating specifications. Right now at my current OC I top out at about 54C. I have not yet adjusted voltage to the RAM, or most of the other voltages except for the CPU core which is below the auto setting.

How can I get this thing up to 3600? Or is that a "hole" as I've seen that just may not ever work? What would a good setup be for the OC of a 6850?

Thanks

 

[myocardia]

Lower your RAM speed to the lowest setting (266 Mhz, DDR 533, or 1:1, depending on what your board calls it). You'll also most likely need a bit more vcore, probably ~1.40v, possibly slightly lower.

 

[miteethor]

Just to put in an update, my second 8800GT SSC came in today so I did a quick install just to see what would happen. I didn't have time to adjust any of the voltages, etc because of wife/kids/life.

My current setup:

e6850@3300Mhz (9 x 366, 1.30V)
G.Skill 2x1GB DDR2-800 CAS4 F2-6400PHU2-2GBHZ @ 800Mhz, 1.8 V default, unlinked from CPU clock
ASUS P5N32E-SLI Plus MB
Tuniq 120 Air cooler with the blue lighted fan
2xeVGA 8800GT SSC factory clocked at 700MHz in SLI

I know some people hate 3dmark but it's all I have at the moment to test:

3dmark2006 single 8800GT with above settings: 12650
3dmark2006 SLI 8800GT with above settings: 15230

I know some people are struggling to hit 10k, but I JUST bought this system and expect it to be as fast as possible. I have seen some Falcon/Alienware/etc getting 18k 3dmarks. Is it just because the bench skews the quad-core processors giving them automatic points or because I have some things that I could tune to be faster? I've swapped my GT SSC with a friends GTS stock for testing and just one of my GT's is faster by about 6-10FPS in most tests.

What else can I do to squeeze some extra FPS?

 

[BonzaiDuck]

If you intend to OC the vid cards even mildly, I think your best approach will be to unhinge SLI, remove one vid card, reset mobo BIOS to defaults, and then find decent improvements to core and vid-RAM. Do the same for the second card (separately). Then pick the lower of the two stable OC's, or just clock them both so they both fit within the limit. I think you would then flash the BIOS of each -- again -- one at a time.

Then reinstall and re-implement SLI. [You'll want to hear that I'm relatively new at vid-card OC'ing, AND that I'm not using SLI, but the guides that I've read over and over suggest this sort of approach.]

You also might want to consider the possibility of tweaking your RAM while you're running it 1:1.

I and a colleague (handle includes the word "nefarious") have been experimenting with low-latency settings on our Crucial Ballistix sticks --- with 1:1 settings. He was more daring than I, and discovered something about tight latency settings with DDR2 that I've yet to try, but I trust his screenies. However -- without pushing you too far in that direction --

The G.SKILL "HZ" modules, if I'm not mistaken, are based no Micron D9 chips. So I suspect they are "promising." See if they don't run at CAS / tCL of 3 at DDR2-667. Whether or not they do, find the lowest stable tCL, tRCD, tRP and tRAS and verify stability at an over-clock (1:1) that guarantees stability at 1T command rate.

THEN, see if you cannot adjust tRC in BIOS for the RAM downward to either tRC = tRP + tRAS, or tRC = tRP + tRAS + 1 Whether it will be one or the other (tighter or looser), will depend on how high your general FSB is set relative to the chosen CAS latency (and this should also hold true for choice of command-rate).

We were able to increase our memory bandwidth "read" benchies by at least 1,000 MB/s with the "write" and "copy" benches up by a more modest 250 to 500 MB/s. My (single-8800-GTS) 3DMark06 score increased by 1,000 points. My benchmark "latency" went down from 74ns to 52ns.

Also -- we could get the same nearly the same bandwidth and latency at FSB 1,333/ DDR2=667 as at FSB 1,424 / DDR2=712. lowering my FSB to 1,408 / DDR2= 704 allowed me to use 1T command-rate and then I got benchies about 500 MB/s higher than the lower 1,333 clock.

But now -- I cannot tell the difference in the "feel" of gameplay at 3 Ghz or 3.2 Ghz. Or -- just barely.

Finally, some of the SiSoft Sandra Memory benchmarks showed that this approach with tighter latencies gives about the same benchies as running DDR2-1000 modules at their rated spec on a divider <> 1:1.

 

[BonzaiDuck]

Also, as far as I can tell, the E6850 has the same retail-box "Maximum voltage = 1.35V".

While my experience is currently limited to E6600 and Q6600(b3) OC'ing, my 3 Ghz setting for the Q6600 Vcore is only 1.32V (rounded up). If you set it as high as 1.41 or 1.42V, the VDroop will probably be closer to 1.37V. And I think, either way, you can probably get from 3Ghz to 3.6 (a 20% OC) with lower vcores.

As to what would be a "good setup," your chipset is different than mine, your processor is different, your D9 memory modules of different manufacture. But -- really -- I do NOT see a 20% over-clock for ANY of these processors -- c2D or C2Q -- to be a big challenge.

For my 680i chipset, I only had to bump up my VTT, 1.2VHT and NB voltages by one notch, or 0.05V leaving SB on "Auto" -- fine-tuning the 3 Ghz (from 2.4) setting. And I was still able to get a 25% OC with the defaults.

But you're starting with stock 3 Ghz, FSB 1,333. And 3.6 is only a 20% over-clock. I'm eager to hear how it turns out. I've heard too many good things about the E6850 C2D. Frankly, even a 33% OC -- closing in on 3.8 or 4 Ghz -- should not be difficult, unless your motherboard sucks . . . . By way of example, I'm running (as I said) the B3 stepping of the Q[uad]6600 -- hotter than your c2D processor revision, and the 33% OC is no thermal nightmare. Well within spec, even at room temperatures approaching 80F.

 

[BonzaiDuck]

Actually, your chipset is the same -- very similar motherboard, too.

 

[BonzaiDuck]

I may have been wrong about the retail "Maximum Voltage" on the E6850. I think the spec was higher on my E6600 than for my Q6600. I also think I had pushed my E6600 to around 1.46V before backing it off somewhat.

Some of us here think that it's not too terribly bad to push the VCORE maybe 5% over the "maximum" spec, especially since the vDroop will put it closer to the spec under load.

But see what you can do for just a 20% over-clock!

 

[miteethor]

awesome - thanks for the input. I can't test this until Friday when I get more time.

Why do these forums show only 3 days? I don't want this thread to drop off before I have time to read it in front of my comp?