Overclocking Escapades: Intel socket LGA1366 Xeon E5640

New CPU came in, time to see what it can do.

Thought I'd see what this Xeon E5640 4C/8T (quad core with Hyper Threading) could do, since the team didn't have any submissions with this CPU.

Stock is 2660MHz, with 2800MHz Turbo Boost speed.

Procedure is same as usual, find lowest stable voltage and then move up from there with overclocking.

CPU: Intel Xeon E5640
Motherboard: Asus Rampage II Extreme
Memory: G.Skill 6GB (3x2GB sticks) F312800CL8T-6GBRM (DDR3-1600/PC3-12800) 8-8-8-24-2T @1.6V
Graphics: Nvidia 7300GS
CPU cooling: Thermalright Ultra 120 Extreme Black Edition with 1x Cooler Master SickleFlow 120x25mm blue LED fan in push and 1x Yate Loon D12SM-12 in pull
HDD: Western Digital Caviar SE 160GB SATA II

Intel Xeon E5640 #1 overclock settings
VID: 1.25v?
2.66GHz (133MHzx20): 1.12v (1.15v)
2.8GHz (133x21): 1.12v (1.15v)-40°C
2.9GHz (138x21): 1.12v (1.15v)-40°C
3GHz (143x21): 1.136-1.144v (1.15v)-42°C
3.1GHz (148x21): 1.136-1.144v (1.15v)-43°C
3.2GHz (153x21): 1.136-1.144v (1.15v)-43°C
3.3GHz (158x21): 1.136v (1.15v)-44°C
3.4GHz (162x21): 1.136v (1.15v)-44°C
3.5GHz (167x21): 1.136v (1.15v)-45°C
3.6GHz (172x21): 1.136v (1.15v)-46°C
3.7GHz (177x21): 1.151-1.191v (1.175v)-49°C
3.8GHz (181x21): 1.164-1.204v (1.1875v)-51°C
3.9GHz (186x21): 1.191-1.230v (1.2125v) +1.224v (1.25) QPI +1.224v (1.25916v) IOH-50°C
4GHz (191x21): 1.204-1.244v (1.225v) +1.224v (1.25) QPI +1.224v (1.25916v) IOH-53°C
4.1GHz (196x21): 1.244-1.283v (1.2625v) +1.217-1.25v (1.275v) QPI +1.270-1.283v (1.31216v) IOH-58°C
4.2GHz (200x21): 1.277-1.330v (1.30v) +1.270-1.310v (1.325v) QPI +1.31-1.316v (1.35191v) IOH-62°C
4.3GHz (205x21): 1.310-1.356v (1.325v) +1.310-1.349v (1.375v) QPI +1.343-1.356v (1.39166) IOH-64°C
4.4GHz (210x21): 1.369-1.415v (1.3875v) +1.316-1.356 (1.375v) QPI +1.343-1.356v (1.39166v) IOH-70°C

What Mobo and cooling are you using ? I got a 5620 to 4.8ish when I first started messing around with 1366. The 56xx series chips clock pretty good.

I'm sorry, inquire on cooling from you guys. 4.8ish on liquid??

Yeah it was liquid, chip probably had more but I was still learning on that one.

Yep, 5600 series were stronger. Also IMC was much better. Not all could make that 4.8GHz on water but most could run at 4.5GHz when Bloomfields were usually ending at about 4.2GHz. Lower chips were usually limited by bclk.
I like this platform but my R3E had couple of bent pins ( fixed , just look weird ) and I always worry it stop working when I put there any new CPU.

Scout said:

What Mobo and cooling are you using ? I got a 5620 to 4.8ish when I first started messing around with 1366. The 56xx series chips clock pretty good.

Click to expand...

The motherboard is an Asus Rampage II Extreme. Frankly, I'm amazed it works at all considering how badly damaged it was when I got it. Socket had several bent pins, fan connectors had bent pins, back edge of the board looks like it was shaved off with a knife (no idea what happened there), and there's a burned trace on the back of the board (which killed some of the rear USB ports). But I've been using it for seven months now for benching and it's been working just fine aside from the USB ports.

It is being air cooled by my Thermalright Ultra 120 Extreme BLACK, with two fans in push-pull.

Funny my rampage III has several non working usb ports burned up ram slots... they still work and the bios switch area looks like it was hit with a hammer lol but it all works mostly. I got my temps better by pushing down the cpu pll if it becomes an issue for you.

Well, looks like this one would need liquid cooling to go any faster. Core temperatures are really shooting up at 4.4GHz, hitting 70°C. And it wasn't always stable, for some reason when it went into screen saver mode the system had a tendency to lock up or crash.

Also, thanks for the tip, Scout. Unfortunately I'm already at the absolute lowest PLL setting though.

I'm betting I could hit 4.5GHz or 4.6GHz if I could just get those temperatures a little lower, or increase the rate of heat dissipation.

What blck is that board capable of ?

Scout said:

What blck is that board capable of ?

Click to expand...

No idea what the maximum is, I've never tested for it.

The highest I've ever had it has been 216MHz.

this has helped me out quite nicely ended up getting 4.2GHz out of my E5640, though it needed 1.375V vcore (though i was doing 210x20) similar mobo in use too, rampage 2 gene.

Hi, thanks for this guide but I was wondering what is the voltage in brackets please ?

Francefire said:

Hi, thanks for this guide but I was wondering what is the voltage in brackets please ?

Click to expand...

The voltages in the brackets are what I had set in the BIOS. The voltage to the left of that is what I saw actually being supplied for that specific component when I checked the voltages in CPUID Hardware Monitor in the OS.

OK thanks a lot

I actually bought this cpu to replace a x5550 I had in my nephews pc. I didn't think about nm size when I made it last year and I wasn't able to hit 4ghz with it while I was quickly able to with this cpu. The reduced heat and temps is great, and the build is perfect for the 7870 I put in the build for him.

I have run the X5660, X5680 (six core0 and a couple of the Quad core X5600 series in this same board.