OC E8400

[jay51]

well i think im making progress,running e8400/ on evga 780i mobo/ 2x1 gb ocz 8500/ i'm at QDR 1700 425fsb /3.825ghz without touching voltage when i go any higher windows boots but fails running prime95 @ QDR 1800 4.05ghz
if i wanted to go higher what voltage would i bump 1st and how much do i add to start?
my goal is to get 4ghz with a 8x multi,giving my 500 fsb so i can run my 8000 ram at 1:1..
is this reasonable?

thanks

[rjbarker]

Glad to see you got her going Jay...is your Memory linked or unlinked?
For 4.05 Ghz try this:
Set vCore to 1.4v (in Bios)
Set Bus Speed to 1800 Mhz w 9x Multiplier (your better off to utilize that Multiplier rather then go for a 2000 Bus Speed (imo)
Unlink Memory and set it at 1066 Mhz - also set to "Expert" - which BIOS version are you using?
Disable Speed Step / C1 yada yada as well as Spread Spectrums and other Spectrums
Leave all other Voltages on "Auto"
F10 and away you go...test vigorously with Prime95 Short FTT's and Blended....I did 18 hrs Short and 6 hrs blended
See how it goes....if all is well, slowly bring down the vCore (testing each time) to see what the least vCore is you can get away with!
Once thats all good n stable, try playing with your Memory, try linking n synching (essentially 1:1, however this will result in your Memory running at 900 Mhz ((450 x 2)) )...if its all good, try leaving it Linked, then uncheck Synched and choose a different Ration, one that will "push" your Memory a little...then re-test!
Its all the Testing that I pretty much now don't have the patience for anymore.......especially since running the IntelBurn Test only to find what I thought was Stable (according to Prime and OCCT) failed the Intel Burn Test...hahahahaha
Good luck....is that the 8800GTX I sold you in that Rig?

[jay51]

i unlinked my memory,set to expert 1066 already
i'll try 1.4v and prime it and see what happens.
not sure bios version ATM ill check next reboot.
yes that's the 8800 i purchased from you :) is 64 to hot?

thanks

[jay51]

i set it to 1.36v only 1.4 seemed like a big jump.. cpu-z shows 1.304 only still??????
1800x9 4.05ghz running prime now i'll let it run for few hrs and see what happens,think i'll put better hsf on tomorrow,i have a vendetta 2 that should keep cpu cooler

EDIT: i upped it to 1.4v OCCT crashed @ 1.36.

[rjbarker]

Man I'm jealous...I got to go to 1.45V to get that OC :(
Thats excellent Jay.
The BIOS version will show up when you Boot into Bios right at the beginning of the Boot Screen loook at the top for some letters n numbers then P0x (x being a number), latest out right now is P08.
vCore - the difference between what you set in Bios and what your seeing Windows (lower) is normal, known as vDrop. You'll also notice that the vCore in Hardware Monitor (get Hardware Monitor as well - free download, just Google it) when your running Prime (underload will drop down even further, this is known as vDroop..also normal.
Also download and use the latest version of Real Temp for monitoring, try not to let Temps get higher than 60 -65c ( I prefer to use 60c as my upper limit, although the Stress Test "IntelBurn" really took the Temps up thier!

The GTX8800 - its been so long...is the 64c idle?...I believe I remember around 70c under load, but its kind of a blur!

[jay51]

bios v6.00pg is all i see
yes thats 64 idle, but fan is not turned up atm,

off to my amd while this stresses :)

[jay51]

hmm,strange runs 3.825ghz on stock volts, now 4.05ghz@1.4v fails/freezes up when running OCCT ..is there another voltage to bump..
eg: fsb or mem?
wonder if it cause cpu was hitting 66c under load
any tips appreciated

[1Tanker]

Originally Posted by jay51

well i think im making progress,running e8400/ on evga 780i mobo/ 2x1 gb ocz 8500/ i'm at QDR 1700 425fsb /3.825ghz without touching voltage when i go any higher windows boots but fails running prime95 @ QDR 1800 4.05ghz
if i wanted to go higher what voltage would i bump 1st and how much do i add to start?
my goal is to get 4ghz with a 8x multi,giving my 500 fsb so i can run my 8000 ram at 1:1..
is this reasonable?



thanks

Not if you plan on running it for any length of time. 500FSB is hard on all chipsets, and without lotsa vNB and extra cooling....i wouldn't suggest it for 24/7. If you run at 445(4.0) or 450(4.05), you can run your RAM @ 1:1 and 890/900...and tighten up the timings and subtimings(using MemSet). Running at the slightly-lower FSB(but much-less stressful) with tighter timings will give you similar performance in most apps; for bench sessions, running at 500 works well.. but some benches like tighter timings vs. higher speed/bandwidth. GL.

[rjbarker]

Are you still running Stock Cooler? Also, yes the 8800GTX does run quite warm, I never was that keen on the Cooling System as it "vents" quite a bit of warm air directly into the Case....but hey, I played Crysis and Bioshcok very well on that Card!
As for your OC and Voltages...without going to my notes:
1. I had a very large jump in vCore required to get stable at 1700 FSB and then 1800 FSB, for example:
- 1600 FSB 3.6 Ghz required vCore 1.275
- 1700 FSB 3.83 Ghz required vCore 1.356
- 1800 FSB 4.05 Ghz required vCore 1.45v
- 1900 FSB 4.2 Ghz required 1.55v - not fully tested, just to complete a 3DMark06 run.
Now in all cases above, all of my other Voltages were left at Auto, as in HT, Vtt (FSB to CPU), Northbridge and Southbridge. I did try lowering my vCore slightly on all settings and bumping up both my Northbridge and Southbridge slightly, but it did not help with stability and simply due to the fact that it now added a couple of more variables to the solution and I had no way to accurately monitor my Northbridge Temps (its infamous in these Boards for getting hot), I decided to just leave those Voltages on Auto. The Evga Forum has a great Thread on OC'ing the 780i and in most cases most folks are getting away with leaving all other Voltages on Auto.
I did a fair bit of experimenting with Lynching n Synching as well as setting various Memory to FSB ratios, but inevitably founf unlinked RAM with Memory set to Factory defaults or "Expert" if Memory is EPP Enhanced Performance Profiles, worked the best.....
Its all extremely time-consuming..all the testing for stability.
AND, having figured all of my OC's were stable, running Prime95 Short FTT's and Blended, overnight in most cases, as well as running Memtest86, I go to run this Intel Burn Test and boom, I fail!!!! uuuugghh..?!

Anyhow, after all that, I have settled now on a 3.6 Ghz OC 24/7,
btw, Intel specs for the E8400 set the "safe voltage limit" @ 1.356v, anymore they advise could cause degradation of the Chip, but (other than one fellow), I haven't heard of anyone frying this Chip with as much as 1.5v 24/7, a;though I had my upper limit at 1.45v (which I ran for about 6 months 24/7).....

Keep me posted...btw...when you OC and leave vCore on Auto, I found that it "Automatically" pumps quite a bit more juice to the Chip then what is really required at that Bus Speed. Thats why its better to set the vCore manually and find the bare minimum!

[enaberif]

Put a good cooler on that thing and pump those volts to 1.42v and go for it. Don't forget to bump your nb voltage a bit and make sure to increase your vTT.