LGA1366 Xeon L5638 Overclock

[Allan74]

I picked up a pair of OEM Xeon L5638's a while back, as an upgrade for my Supermicro X8DTi-F v2 system, but for some reason the system wouldn't post with both installed, although had no problems running 1 at a time. Oh well....moving on.

Having the pair of 32nm Xeons just sitting around, I figured I would throw together another rig to play with, as running a Dually-LGA1366 Rig has taken me out of the loop in terms of overclocking, as there really wasn't anything other than the power button to play with on the Supermicro setup.

I can't seem to find too much in terms of overclocking ability with these CPUs online, as they are only 2Ghz units with a low multiplier, so not very common or desired.

I threw one of them into a Gigabyte X58A-UD5 board that I had kicking around to see what it would do.
1st boot, stock. Obviously no problems.
2nd boot, 166Mhz FSB....clean boot.
3rd boot, 200Mhz FSB and still clean & stable.
4th (where I am now), 210Mhz FSB, everything left on 'AUTO' in the bios and still, another clean post/boot to 3360Mhz (16 x 210Mhz).

Here is the validation link for those interested: http://valid.canardpc.com/2738601

....or, a pic for those not wanting to click:


My question (FINALLY) is, is this kind of V+ safe for a 60W CPU ? (1.376V) ?

Again, everything is still on AUTO in the BIOS, so now I will begin fine tuning, as the rig has only even been booted a handful of times now, but all seems stable thus far.

Also, while I am here.....
Any ideas on why my Supermicro X8DTi-F v2 won't post with both L5638s installed ?
It's currently running a pair of X5550 ES Chips, without problems, so I figured that the new OEM chips would be an easy installation, but I was shown otherwise.

Thanks in advance.

<EDIT>
I decided to put the Single overclocked Xeon head-2-head with my Dual-X5550 Rig and here are the results:

Handbrake - 720p TV Episode h264 Transcode
-------------------------------
Completed in 29:40 (Dual X5550 @ 2.67 Ghz, 16 threads) 34 fps avg.
Completed in 25:25 (Single L5638 @ 3.36 Ghz, 12 threads) 40 fps avg.

Using the same settings on both units, looks like the single Xeon is a bit quicker than the Dual-Xeon.
For the time being, it looks like this single might be an upgrade on it's own.

[tool_462]

As far as voltage goes, Westmere can handle 1.376v all day long.

I assume your X8DTI-F v2 is updated to the most current BIOS? Either way, e-mail Supermicro and they often will be able to make you a BIOS or send you an unofficial one that will support any CPU you ask them to support.

[Allan74]

As far as voltage goes, Westmere can handle 1.376v all day long.

I assume your X8DTI-F v2 is updated to the most current BIOS? Either way, e-mail Supermicro and they often will be able to make you a BIOS or send you an unofficial one that will support any CPU you ask them to support.

That's comforting, about the voltage. Thanks.

As far as the Supermicro board, I figured I would do some preventative maintenance and update the BIOS to the latest (still the only one on the site) prior to throwing the new L5638s at it, but to no avail, that still didn't seem to help in the end.

I will contact Supermicro support and see what they have to say. Even though the L5638s are not really an ideal upgrade for the X5550s on paper, I simply wanted the lower power consumption and less heat in Dual config.

With the L5638 CPUs being 2Ghz @ stock and the fact that I have 1 running stable @ 3.36Ghz, I now want to see if I can push it to 2x stock and hit 4Ghz with it.

Is there a SAFE voltage for 24/7 use, or one that I should stay away from with that 32nm CPU ? (if I continue to knock on the door of a 2Ghz overclock ?)

[Allan74]

Looks like my 'AUTO' Settings luck just hit the wall: http://valid.canardpc.com/2738683



Now, it's time to begin actually using the settings in the BIOS and any suggestions or advice is appreciated.

It's currently seeing a max of about 65c at full load using a Skythe Katana, but I have an old Thermalright Ultra120 with dual fan cups so that I can run push/pull that I am going to be blowing the dust off of and installing for further overclocking.
I am going to keep this thing on air cooling.

Cheers,
Allan

[chris89]

It seems to me the L5638 will be limited by the multi and fsb. Your not likely to have a true stable on the x58 beyond 200mhz fsb because of the QPI link speed and Uncore clock. Make sure they are at a 1:1 meaning the Uncore is half of the QPI for stability.

At 200mhz fsb on a 4.8GT/s i7 at 200fsb it's not stable at anything beyond 7209Mhz QPI, and 3609 Uncore. The uncore can go as much as 4Ghz but see stability issues but higher memory speeds and GFLOPS output. However it hates Asymmetrical uncore : qpi ratio. Since out of sync the Uncore is running faster than the QPI theoretically so it still has to catch up to the Uncore speed so it's an Up Down performance benefit. Solid gains and Solid losses across the board.

Anyway I don't see any 1366 chip loving it beyond 7209Mhz not even on water.

That's why you want a high multi and according to what I have read the L5638 stocks at 2Ghz and boosts to 2.4Ghz meaning the stock multi is 133 x 15 and the boost is 133 x 18.

Meaning you have x18 to work with so turn it to 200fsb, 3609 uncore, 7209 qpi to sync it up. On DDR3-1600 ram that would allow DDR3-1603 so a bit of a boost in overall memory and cpu performance.

So that in mind we can see as high as 1.475v with intel spec vdroop enabled for peak overclock.

Using a Indigo Xtreme 1366 interface with upwards of 25W/m*K of thermal conductivity transfer.

I'd lap the L5638 and the cooler to 100% pure flat copper.

Then we could see peak potential of 200 x 18 = 3600Mhz peak.

If you want 4Ghz then you'll need the L5639 bare minimum since it'll do 200 x 20 max at 4000Mhz.

A bit more at 4.2Ghz max is the L5640 and L5645 since they have a 21 max multi so 200 x 21 = 4200Mhz.

Good Luck!

[Shiranui Gen-An]