i7 860 @ 4GHz, HT on (24/7 Use: Y/N?) - Overclock.net

ItsMeMark · 3 Weeks Ago

What is a reasonable temperature on load for 24/7 use on an i7 860?

What other factors should I consider before keeping the chip at 4Ghz?

Goals:
1) i7 860 @ 4Ghz (HT on) for 24/7 use, stable, >80C temps
2) RAM at 8-8-8-24 or better @ ~2000mhz
3) Fix this Windows 7 incompatibility hate
4) No fires

I read up on the forum and noob OC guide (first OC here) but had a few things that went unanswered. Anyone who owns a EVGA P55 FTW that can tell me how to do this step by step would be AWESOME.

Keeping a record of all my findings because this is listed on Google already.

How do I drop the CPU multiplier? (Figured it out: use the +/- buttons)

What is the highest "safe" Vcore for the i7 860 (most guides were for the 920)? (Answered: 1.5V but keep it around 1.45)

At what temperature should I manually power off the CPU (I'm watching the littler display on the mobo very closely.)? (Found out: CPU will shut down at 100C, 90C is considered high)

If I was able to get into the Windows XP loading screen at 4.4Ghz, then BSOD, at the same volts listed on that validation, is that any kind of achievement (Rephrased: Should spend the time to go back and get a validation even though I know it won't be stable?)? (Answered: Unless is an insane amount closer to 5Ghz, don't bother. Stable or bust!)

Again, this is my first OC so any suggestions would be awesome but keep it as noob friendly as possible.

(Also, my system HATES Windows 7 so I'm using Windows XP in all this testing.)

Pillz Here · 3 Weeks Ago

I'm not sure how the EVGA P55 bios is but the multiplier in my bios is the "CPU Ratio". I have mine at 21x so I changed the ratio to 21.0, so if you want it at 19x you would change it 19.0. You can try that, but every bios is different.

Rightwing · 3 Weeks Ago

Hit up Foxhound over in the 1156 club he's got that mobo and over clocked it.I am not going to over clock until I get an after market cooler around Christmas, so I can't help ya myself sorry.

FSF-Foxhound · 3 Weeks Ago

got your PM, alright here we go.

Highest safe Vcore would be around ~1.43 for Foxconn sockets, however I belive the P55 ftw ships with lotes or some other socket brand. You can use up to 1.50 on any other socket but foxconns. the reason behind this is that at higher voltages the foxconn sockets can destroy your CPU via some power problem of some sort. You probably won't get a OC high enough to use 1.5 Vcore anyway. Intels spreadsheet does not say anything specific about the i7 800 series, just 1.55 for all nehalem CPUs.

A noob version of that: stay under 1.50. you probably won't need 1.50 for any OC the 860 can achieve.

The temp to turn your comp off is 100C, which it would shut itself off/cool itself off down automatically anyway. however keep it below 86c and you're ok.

Don't except a i7 860 to get even 4GHz with near to stock volts. I am yet to see a i7 860 with a 4GHz OC stable with even 1.35. You might need about 1.4+.

The i7 8XXs don't usually reach over 4.2GHz for 24/7 use, so keep that in mind.

As for the ram, I'd pick 200 BCLK with a x21 multi for 4.2 GHz, as that usually gives you the same options as 133Mhz (stock). Set your CPU VTT to 1.45 in the BIOS to achieve 2000MHz overclocked.

In the BIOS you can find it under "bootup CPU VTT" and "Eventual CPU VTT". Set both to 1.45.

Let me know If I missed a question.

ItsMeMark · 3 Weeks Ago

Tried all sorts of variations for 4.2Ghz and I just could not get it stable. Darn. The worst part is I am 90% sure it will go higher.

4Ghz @ 1.376v (meaning I should be able to pump it and get more)
84C max (mobo display) and I read that 100C is the danger zone so the temps are not that bad (?)

Looks like I'm stable at 4ghz though and I'll probably turn down the Vcore to get it as close to stock as possible. The real question now is how 4Ghz 24/7 will hold up.

DUNC4N · 3 Weeks Ago

4ghz isn't bad at all.

If you don't mind could you do a 3dmark06 run with your setup at 4ghz and post a result?

I was debating on going the P55 route, but want to see some real people benchies to determine if its worth it.

thanks.

kyleax1 · 3 Weeks Ago

I tried for over a week to try to get stable at 4ghz with ht on with the megahalems, just won't happen for me without watercooling.

4ghz at 1.44v HT on running IBT, it would fail by loop 3 and would top out at 92c. You can load into windows at 4.4ghz or higher with ht on, but the second you go to run a stress test it will crash.

The best I could get stable at was 4.1 ghz with HT off at 1.42500v
With HT on I could not get stable at 4ghz 1.44v and since I don't want to go under 4ghz I decided to just keep HT off.

To DUNC4N - Click on my "Intel Sniper Project Pics" in my sig and you can see my 3dmark scores. They are at 4.1ghz with HT on and 5850 at 940/1300. Even though I couldn't get stable at that spped with HT on I was able to run the benchmarks. At the same speed with HT off I was getting between 500-900 points lower on vantage and 06

FSF-Foxhound · 3 Weeks Ago

I find it odd your temps are that high with the megahalem..

ItsMeMark · 3 Weeks Ago

Yeah I did a little looking around and 85 is pretty high. I'll run some real temp readings soon.

1 hour into Prime95. Looking good.

Cpu-z is saying I'm jumping between 1.376-1.388 V. I'll check this with other programs after Prime95.

kyleax1- Ouch... I was able to boot at 4.3Ghz and probably could have gone to 4.5 by pumping the vcore since I was always under 1.45V (always HT on). I just could not get this thing stable at 4.2Ghz and now that I see my 4Ghz readings, I probably couldn't have gone that far anyway.

I think I have my fan facing the wrong direction... Plus it's just a one fan, pull setup. I'll need to get some 2150rpm Gentle Typhoons when I see a deal on them.

kyleax1 · 3 Weeks Ago

Get a 120x38mm fan or 2 for push pull.

I have 2 push/pull + 2 fans pulling air from my drive bays directy into my push fan on my heatsink(adding the 2 fans to the drive bays lowered my load temps by 3c).

at 1.425v and 4.1ghz running Intel Burn Test set to maximum using 4 threads (since HT is OFF) and an ambient of 21c I max out at 86c after 7 loops

If you haven't already, download IBT

Set it to maximum for ram usage, set the threads to 4 if HT is off and 8 if HT is on. Set it to run 10 loops and just see if you can get through 10 loops without it giving you a warning.

I thought I was stable running Prime 95 and realized very quickly with IBT that I wasn't even close to being stable.

If at any time during the 10 loops you get over 90c on any core you will prob want to lower your oc or your voltage if you can. HT being off will lower your max temp by 8'ish degrees.

If you pass 10 loops it does not mean you are stable, but it's a good start.

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i7 860 @ 4GHz, HT on (24/7 Use: Y/N?)

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