overclocking my new i5-750

[Nhut Pham]

I've been on these forums for the longest time, and while I see many push the limits of overclocking, I tend to push the limits of well, my budget.

I've always been one of those people that bought the "mid-grade" level pieces, and tried to get the most value out of those parts by overclocking them best I could. I live within spitting distance of a Fry's and a Microcenter, and I've been an online deal hunter since before I joined this forum. So I jump on what I can.

I recently picked up the i5-750 + Gigabyte p55a-ud3 combo from Fry's for 209 after rebate, i5-750 combos have been going on at Fry's like this for sometime, but often I would go to Fry's at lunch time and they would already be sold out of stock in the entire bay area. This last sale I walked in and there were 3 mobo's laying there, I half thought about going back in to buy the extras. The Gigabyte board is probably the best board they've comboed with the 750 so far. The i5-750 I got had a higher batch number than any I've seen posted on any performance forums, L950B649.

I'm using some RAM I got from a friend for free, he had extra sticks of DDR3-1066 laying around so I've been trying to overclock before the return period on this combo is up. (I have some Ripjaws on the way thanks to invisible hand, but I might not even need them)

I don't see a lot of overclocking results on these forums besides in sigs, so I'll put up my trials here.

I started by putting my RAM to the stock limit, putting the CPU at 177x20 with all settings to auto, everything runs great, simple as that. RAM's at 1066 speeds CAS 7, processor 3.56ghz or something like that. Comparing the speed to my last setup, a q6600 at 3.8ghz, I really don't notice that much of a difference.

Next I try giving the RAM a slight overclock to 1200mhz CAS 8, as I see this setting in the memory tables in CPU-Z. I put the processor at 200x20 with voltages on auto, everything runs perfectly, much to my surprise. I play around with voltages and end up with a stable 4ghz overclock at 1.280V (1.300V in bios) and VTT untouched at 1.1V. Temps max out around 72 degrees.

So I try to push the multiplier to 21 and see if 4.2ghz will be just as easy. I bump the voltage to 1.325 (1.35V in BIOS) and prime errors after a few minutes. I go back and bump the QPI/VTT up to 1.3V, and what do you know, runs fine. I tried lowering the voltage some, but only was stable one step down, at 1.312V (1.343V in BIOS).



Overclocking should always be this easy. I never got BSOD during testing, something I'm not used to. I was also surprised by how well the Gigabyte board would get voltages while set to auto, in the past I was always used to the board going much higher than what was needed.

I'm gonna try to clock a bit higher soon, a little scared because temps are high. I'm reusing my Xigmatek HDT-S1283 from my 775 build, with the 1156 adapter bracket. Not really willing to shell out more money to drop the extra 4-5 degrees, I'm hoping the AS5 cures and I drop 1 or 2. Especially since I just bought a 5850, the single most expensive piece of computer hardware I've ever bought. To give you an idea of how much I've spent on this upgrade:

Xigmatek 1156 bracket -$10 (seriously, 775 to 1156 to 1366 is off by like a few mm, did they do that on purpose)

CM Storm Scout + 600w ModXStream - 60 after rebates
previous Antec 300 + 500w StealthXStream - sold for 50

i5-750 + Gigabyte p55a-ud3 - 209 after rebates
q6600 - sold for 120, Asus P5Q-E hopefully sells for 70?

Super Talents being used - Free gift (shameless plug, I have 4 sticks of 4gb in the classifieds)
G.Skill Ripjaws DDR3-1600 CAS 7 - 100 (might just sell these)
previous OCZ Reapers - sold for 65

ATI 5850 - 227 after rebates (yeah, I don't mind 1 year warranty)
previous 4850 - sold for 80
current GTX 280 -selling soon, maybe $200 on ebay?

 

[doz]

This combo was excellent. I just bought two for a couple other guys and shipped them off (they dont have a Fry's there).

I got this combo as well. Im stable at 1.264v @ 4ghz. Set it and forget it, was a cakewalk. Maybe my experience with i7 was helpful, but like you said, its not nearly as tricky as getting 4ghz on Core2's IMO.

For some reason, I havent pushed farther than 4ghz yet, I need to.

 

[PolRoger]

So I try to push the multiplier to 21 and see if 4.2ghz will be just as easy. I bump the voltage to 1.325 (1.35V in BIOS) and prime errors after a few minutes. I go back and bump the QPI/VTT up to 1.3V, and what do you know, runs fine. I tried lowering the voltage some, but only was stable one step down, at 1.312V (1.343V in BIOS).

200x21 with ~1.312v load... looks like you have a pretty nice chip! I agree that the Xigmatech looks like its having a little trouble with the heat load at that overclock. Have you tried running with the 2:8 divider at DDR3-1600?

 

[Nhut Pham]

Haven't tried 2:8 yet because my Ripjaws are in the mail. I could try to push this memory some more, but I think 1600mhz from 1066 ram might be pushing it (although I saw a review somewhere that did it with Patriots).

I've seen a lot of benchmarks that show very little difference between DDR3 ram speeds and timings when it comes to real world apps or games. Almost all the difference is in all the memory benchmarks out there, which I don't really do. If I get a better overclock or the computer feels faster with the better ram, I'll switch to it. Otherwise, I'd rather have the 8gb dual channel over 4gb.

 

[Brutal-Force]

Your temps, while a little high, are still within limits for a 4.2 Overclock.

Those voltages are very nice for 4.2 you could probably do more, although a better cooler would help you drop a few degrees.

When I had my i5, it would do 4.2 but took almost 1.45V. I never have any luck with processors.

 

[Nhut Pham]

This combo was excellent. I just bought two for a couple other guys and shipped them off (they dont have a Fry's there).

I got this combo as well. Im stable at 1.264v @ 4ghz. Set it and forget it, was a cakewalk. Maybe my experience with i7 was helpful, but like you said, its not nearly as tricky as getting 4ghz on Core2's IMO.

For some reason, I havent pushed farther than 4ghz yet, I need to.

Yeah, I don't really feel any difference from 4ghz to 4.2, I just want to really see how far I can go with this chip before I settle on a setting for 24/7 use.

I noticed you got a nice overclock on that 5850, I hope mine does that well too!

 

[Nhut Pham]

Your temps, while a little high, are still within limits for a 4.2 Overclock.

Those voltages are very nice for 4.2 you could probably do more, although a better cooler would help you drop a few degrees.

When I had my i5, it would do 4.2 but took almost 1.45V. I never have any luck with processors.

The batch number I got means I probably got one of the newer chips they've made. Maybe Intel is getter better yields recently, I've seen a lot of i5 with batch numbers past L935 and up have pretty low voltages.

I think I past a heat threshold around the 1.33V (BIOS setting) mark. Stress testing at this value and lower would top out at 72-73 degrees, within Intel's spec (probably better in terms of processor degrading). Above this would result in temps that top out around 78-80.

Trying out different games, I never go above 56 at 4.2ghz.

 

[doz]

You should be safe w/ load temps up to around 85c. I test in LINX and get 66c loaded @ my current settings.

Oh, my Batch # is L940B745

 

[Nhut Pham]

Dang, that's pretty good, what kind of cooling are you running?

 

[Nhut Pham]

So I went through RMA with my last i5-750, because of scenario mentioned here, and I got a new one from Intel.

It is a very recently produced chip, pack date was 4/27/10. It has a fairly new batch number, L003B806, manufactured 3rd week of 2010.

Compared to my last i5-750, it's a little more voltage hungry but runs a bit cooler. It also requires less VTT. For the same 200x20 overclock, the comparisons between the two chips manufactured 5 weeks apart, both on the same S1283.

L950B649

Vcore@4ghz: 1.30V bios, 1.28V cpuz
VTT: 1.29V
Idle Low(c1e): 29-22-29-24
Prime95(large): 69-70-64-69
LinX(10000): 71-72-65-72

L003B806

Vcore@4ghz: 1.343V bios, 1.328V cpuz
VTT: 1.19V
Idle Low(c1e): 25-23-26-25
Prime95(large): 65-64-61-63
LinX(10000): 68-67-63-65



I'll try out 4.2 ghz next, might wait for my VX to get here in the mail first.

Strange thing though, it seems like some people are stealing posts from our forum...is this arabic?