[Kal-EL]

Setup:

Processor | Core i7 875K |4 Core 8 Threads| 2.93ghz | 8mb cache| Socket LGA1156 | SLBS2 | Batch# L004B840

Mobo | EVGA P55 200 Classified Motherboard

Corsair GTX1 | 2GB | 2400mhz | 9-11-9-27 | 1.65v | ver8.1 | 2 sticks

PSU | Silverstone 1500w

OS | xp (lite)

Cooling | Dragon F1 EE + Ln2


Benchmarks | 2D stuff

Click and browse thru the benches:
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Quick Session: I was bored with the dancing Storm Troopers on the MSI MOA 2010 Livestream so I decided to see what this Intel 875K chip was about and started a really quick bench session.

Cold Bug: -120c
Cold Boot Bug: On Hard Lock it was mostly a -60c Cold Boot Bug. But, on occasion the cbb moved to -85c and -105c.

X-Cool/Xtreme Cooling: the x-cool jumper and xtreme cooling modes on the EVGA P55 motherboard do not appear to be suited for this particular K-series chip. Stability was worst at higher clocks and the board exhibited signs of cold issues past -100c with the x-cool jumpered. The best results were had with x-cool not jumpered and Xtreme cooling modes disabled. EVGA may be able to improve this function with a bios update but as for now it doesnt appear as a useful feature on this chip.

Vcore Voltage: This particular chip did not enjoy any voltage above 1.478 Vcc no matter how cold. There doesnt appear to be much scaling above 1.43vCore.

Vtt: best results were at 1.275 vtt, upwards did not help stability at higher clocks

PCH: 1.475 gets the job done while 1.35 was hit or miss.

vDimm: 1.70 thru 1.73 allowed for the chip to behave in wprime and made no difference in pi at the upper end clocks shown above.

Signals: All signals were maxed -31

Multiipliers: This chip has an unlocked multiplier but so far it appears to be next to useless. 26 worked well and so did 25, but 27 thru 30 were rubbish.

K-Boost: I didn't play around too much with the K-Boost feature available in the bios for K-Series chips but what it does is auto set the multi to 27. Any monkey can do that.

Boot up: I found the most stability booting in at around 170x26=4420mhz 1.45vcc 1.275 vtt 1.70 vDimm @ -60c (increase clocks voltages in OS as needed)

Scaling: This chip scaled with voltage for the most part not cold. At -60c and 1.43vcc I was able to blck all the way up to 195 without touching the voltage on the first boot. It was wprime capable thru 195 bclck as I poured down to -85c towards the end.

Fine Tuning: I tested a number of singalling, timings, sub-timings, qpi settings and voltages settings. It appears that the lowest QPI setting w/mch strap to dram/ratio was the most effective/functional setup.

Thats it for my quick summary regarding the Intel 875K chip. Thank you for reading

[DOM]

Still did a good job with it not playing nice

[Kal-EL]

Chip feels restricted somehow, may have to investigate further. -100c should be yielding alot more headroom.

[Hondacity]

one 875 i tried had cb @ -40c

LOL

[Kal-EL]

I'm betting you still had cpu clocks near 5ghz?

[Hondacity]

cpuz 5.2ghz

[DrNip]

How do ya like the P55 Classy supes? Was thinking of picking one up for my i3, i5 benching. That or the UD7.

[Splave]

I look forward to more threads like this.

Did you try pushing the ram any faster than 9** cas8?

[overclocking101]

I ended up switching boards when I got my K cpu. my EVGA P55 board did not play nice with it at all. I am unsure why, maybe due to evga's bios focus at the sr2 idk. but when I switched boards to my current one my cpu performs a lot better, my only regret is for some reason evga P55 boards are amazing with high ram freq and tight ram timings but this board is not.

[Kal-EL]

Originally Posted by Splave

I look forward to more threads like this.

Did you try pushing the ram any faster than 9** cas8?

Yah Splig, I've a few cas 8 screenies in there but didn't see the sense in wrenching it down just yet because I wanted to get the cpu clocks much higher before doing that. So I tried running loose to give some leeway but its likely a bios dealio. Shammy must be on Holiday or something, he's MIA.

Originally Posted by overclocking101

I ended up switching boards when I got my K cpu. my EVGA P55 board did not play nice with it at all. I am unsure why, maybe due to evga's bios focus at the sr2 idk. but when I switched boards to my current one my cpu performs a lot better, my only regret is for some reason evga P55 boards are amazing with high ram freq and tight ram timings but this board is not.

to the forum, which board did you switch over to? and which K cpu did you use?

I'll pop this chip into the MFIII soon and compare capability.