X.M.P causes CPU to overheat BADLY

[Rookie92]

Hi all, just registered here to ask a question as i often find useful info on toms hardware a few days ago i finished my first pc build, everything's running great and im chuffed with it but there's just one thing thats annoying me...

Im running an i5 750 on gigabytes p55a-ud3 motherboard with 4gb's of G-Skill Trident 1600 Cl8 RAM.

The board and the memory both support X.M.P but when i enable it in the BIOS it causes my CPU to massively overheat, with x.m.p. on, it idles around 50 c and within 2 minutes of being put under full load it will hit high 80's and soon into 90's. I thought i maybe didnt install the cooler properly (its not aftermarket and i stuck with the thermal grease that is initially on the base of the heatsink) but when i checked it was definitely on as it should be. I then tried turning my X.M.P off and my temperatures went to were they should be, 38ish at idle and 68ish at full load. Im just wondering why this is, i have done no manual oc'ing (just swithching my x.m.p on and off) and with x.m.p on the memory was running at its advertised speeds and timings, at 1.6 volts (as opposed to 1.5 without x.m.p). Anyone else noticed anythig similar? Have a solution? Thanks

 

[wolfram23]

The XMP profile is increasing your base clock from 133 to 160 so it is overclocking your CPU. Overclocked CPU = more heat. You'll need an aftermarket heat sink to run XMP. IMO, run your RAM at 1333 with lowered timings (7-7-7-21). You can try slightly overclocking to 140bclk for 1400mhz CL7 RAM which should work, maybe even 141 or 142bclk same timings will work. Just watch those temps. Also, make sure you enable C1E, EIST, and C States (at least C3, C6 is better) and it should drop the idle temps.

 

[wolfram23]

Ah that's interesting. Well, even at a similar clock speed the higher bclk will need a little more voltage. I don't know much about the Gigabyte BIOS but sometimes it will show your current voltages as well as the set voltage... Assuming it's all on auto, try booting with XMP off and check the Vtt and Vcore volts, then load XMP and reboot to BIOS and see if they're higher. The Vtt should be a tad higher due to the baseclock. The temps do seem a little too high tho, I'm wondering do you know if the fan is speeding up? Can you hear it? You might have to enable a smartfan feature or even run Speed Fan - my last mobo, an MSI, had crappy fan control generally not turning it up for a while after the cores heated up while my new ASUS mobo works great.

 

[Rookie92]

Thanks Wolfram, that sounds like a good alternative though one thing i wonder about is that when it increases the bclk to 160, it decreases the multiplier from x20 to x 17 (i checked the effects of XMP in BIOS), which results in a clock speed of 2720 (if my basic understanding of oc'ing is correct), but this is only a total increase of 60mhz compared to a 133 bclk with 20x multiplier, could this really cause such a drastic temp rise? Especially considering the processor is supposed to support turbo boost up to 3.2 ghz!
Thanks again for your advice, very helpful considering my lack of experience dealing with clock speeds, latency timings and voltages

 

[Rookie92]

Im not sure about the fan, ill have to check that, i checked the voltages, with XMP Vcore was 1.248 as opposed to 1.08 without XMP. Im not sure what Vtt Voltage is but there was a reading for a "QPI/Vtt Voltage", which was 1.1 at both settings, and the XMP bumped my DRam Voltage from 1.5 to 1.6 i also realised that with out XMP its latency timings are 9-9-9-24 so can you read anything into these numbers? Does more volts = more heat? But they are necessary to run higher speeds without crashes and Bsods? That right? Thanks a mil

 

[wolfram23]

You probably don't need that much vcore, looks like XMP is just overvolting to "make sure". Yes, it's definitely going to add more heat. As for the memory timings, that's just the default spec you can manually change them. Auto isn't necessarily going to give you the right numbers. Heat is your main issue here, but theoretically you could probably get away with 160bclk, 20x multiplier with turbo on, at 1.2V Vcore and set the RAM to 1600 8-8-8-24... But obviously heat's an issue so like I said before, I'd probably leave it lower like 133 or 140 bclk with turbo on and the RAM set to 1400 7-7-7-21. See if that works and what temps you get. And try leaving the voltages at auto/stock (well, not including the DRam Voltage that should be 1.6 or 1.65V depending on the manufacturer specs... 1.65 is normal but don't exceed that)

 

[Rookie92]

Cool, so i got my timings to 7-7-7-21 and it all seems stable and temps are fine. I think ill leave the base clock alone for the moment though, seeing as such a tiny oc caused a 30 degree rise in temperature before! I dont need the extra few mhz anyway really, runs perfect as is, nice to be getting what i paid for out of my memory though, even if its not as intended Thanks for you're help wolfram, much appreciated!

 

[jordanrhughes]

So I'm genuinely curious what the threshold is for cpu temps, as in, what should be considered the 'red' zone.
I ask because recently while playing some EQ2 I would get short 3 or 4 minute stretches of incredible framerate loss. After some extensive testing and banging my head against my keyboard I finally noticed that during those periods of performance loss my CPU was getting throttled to 50% of the max frequency, which of course was choking out performance (especially since EQ2 is so cpu intensive).
So I installed CPUID I watched my temps while running the game. When the CPU was throttled, the temp would show a sharp decrease, then slowly start climbing again after my framerate returned to normal.

I'm guessing it's either a function of Windows 7 which is causing the throttle or a BIOS setting in order to allow the CPU to cool.
The temp capped at around 81 C. Is this an ugly temp? I'm half tempted to try and track down the setting and disable it but of course I don't want to cook my PC.

It just feels to me like 80C or so can't be THAT bad, can it?

_____________________
maui hotels deal anyone?

 

[wolfram23]

No problem, glad to help. Just remember that for about $40 you can get a new CPU heat sink and then you can overclock to your heart's content. (Hyper 212+ is probably the best cheap one) As my signature shows, I'm running an i5 750 at a pretty good overclock of 3.7ghz and turbo up to 4.2ghz. 175 base clock. I have similar RAM to you, 1600mhz CL8 but I under clocked the speed to 1400mhz just because that works better than at 1750mhz, and then tightened the timings to CL7. My temps are around 30C idle and absolute max with Intel Burn Test is 63C

(btw, if you do the "select as best answer" it's often appreciated in these forums )

 

[wolfram23]

So I'm genuinely curious what the threshold is for cpu temps, as in, what should be considered the 'red' zone.
I ask because recently while playing some EQ2 I would get short 3 or 4 minute stretches of incredible framerate loss. After some extensive testing and banging my head against my keyboard I finally noticed that during those periods of performance loss my CPU was getting throttled to 50% of the max frequency, which of course was choking out performance (especially since EQ2 is so cpu intensive).
So I installed CPUID I watched my temps while running the game. When the CPU was throttled, the temp would show a sharp decrease, then slowly start climbing again after my framerate returned to normal.

I'm guessing it's either a function of Windows 7 which is causing the throttle or a BIOS setting in order to allow the CPU to cool.
The temp capped at around 81 C. Is this an ugly temp? I'm half tempted to try and track down the setting and disable it but of course I don't want to cook my PC.

It just feels to me like 80C or so can't be THAT bad, can it?

You have an i5 750? From what I've read it shouldn't throttle till around 95 or 100C. 80C is definitely very hot but it shouldn't cause throttling. I'm guessing you must have enabled CPU throttling at a lower temp... might be a BIOS feature. How old is the PC? I'm guessing stock cooler and you overclocked it right? Have you tried cleaning out the dust from the heat sink? Does your case have at least 2 or 3 fans? There's a lot of little things you can do to lower temps, but getting an aftermarket heat sink should be #1

 

[Rookie92]

Yeh when it starts to struggle ill splash on a cooler as for Jordan before i realised my heat problem my 750 got to 99 c and then just switched off playing BC2! So id say it is a setting in your BIOS. According to Intel the max core temp is 78, but 80 isnt going to kill it immediately but it may shorten its long term life a bit lol and i'll be sure to find that button Wolfram!

 

[Rookie92]

Couldn't find it... If you can guide me I'd be happy to oblige

 

[wolfram23]

Couldn't find it... If you can guide me I'd be happy to oblige

lol Should be just on the bottom right side of each reply, near the Reply button.

 

[Rookie92]

lol It just isn't there man i swear! Maybe i dont have permissions or something, there's just the "Reply to Wolf..." button and an "add this to list of quotes" button...

 

[davcon]

Hi all, just registered here to ask a question as i often find useful info on toms hardware a few days ago i finished my first pc build, everything's running great and im chuffed with it but there's just one thing thats annoying me...

Im running an i5 750 on gigabytes p55a-ud3 motherboard with 4gb's of G-Skill Trident 1600 Cl8 RAM.

The board and the memory both support X.M.P but when i enable it in the BIOS it causes my CPU to massively overheat, with x.m.p. on, it idles around 50 c and within 2 minutes of being put under full load it will hit high 80's and soon into 90's. I thought i maybe didnt install the cooler properly (its not aftermarket and i stuck with the thermal grease that is initially on the base of the heatsink) but when i checked it was definitely on as it should be. I then tried turning my X.M.P off and my temperatures went to were they should be, 38ish at idle and 68ish at full load. Im just wondering why this is, i have done no manual oc'ing (just swithching my x.m.p on and off) and with x.m.p on the memory was running at its advertised speeds and timings, at 1.6 volts (as opposed to 1.5 without x.m.p). Anyone else noticed anythig similar? Have a solution? Thanks

Wow! sure sounds strange to me. I have an 860 running on a Gigabyte P55-UD5 with Corsair Dominator 1600MHz ram.
Enabling XMP has no effect whatsoever on my BCLK,sure it increases my temps slightly but that's to be expected.
I dont think our bios settings are much different since i also have an H55 Giggy mobo with 1600MHz ripjaws XMP enabled no BCLK change there either.
If i were you i would reset/clear my CMOS
Enable XMP
Adjust DRAM voltage
save and exit
should run as advertised
don't touch anything else in bios.

 

[Rookie92]

Thats interesting, how does your X.M.P profile increase the memory speed from 1333 to 1600 without increasing BCLK? What would happen by clearing Cmos? Because i had the mobo brand new and didnt touch anything except my XMP setting, is that the same as a clear cmos? Also when i enable XMP it automatically increases my DRAM voltage to 1.6 V's... Any more info you have would be appreciated though im in Ireland and its late so i might dis-appear from the forum for 10 hours or so!

 

[wolfram23]

Hmm well clearing CMOS just resets the BIOS... plus XMP's are dependant on the brand and type of RAM. If you're running 1600mhz RAM the XMP has to OC your CPU to 160bclk... it just has to. However, sometimes XMP has several settings. If you look in Everest you can see them but they're not always attainable throught the BIOS. For example my RAM has XMP profiles 1 and 2. Within Profile one there's 3 different settings, I forget the lowest but then it's 1400 CL7 and 1600 CL8. For XMP Profile 2, it's considered the "extreme profile" and boosts voltages up to 1.7 for 1400 CL6 and 1600 CL7. These do not work at all for me, I tried up to 1.75V but no go.
I'm guessing if it's not adjusting the BCLK, it must be enabling the lower XMP Profile 1 setting. Either way, if it's the same speed and timing as doing it manually, then it doesn't matter.

Davcon, if you could maybe post a pic of CPUZ shoing the CPU and Memory tabs we could get some info...

 

[Rookie92]

O.K. one last post and then seriously I'm going to bed! And when i wake up i expect solutions to all of lifes problems right here on this thread ! I actually do have a memory setting in BIOS "Performance Enhance" that refers to "standard" "turbo" and "extreme" settings, but i wasn't sure what that meant, but it looks like what you're talking about, it defaults to "turbo" and i haven't experimented with that at all...

I'd also like to see a scrnshot of Davcon's CPUZ too, that could be helpful... Anyway good night! Thanks again, still no joy finding that button!

 

[Crashman]

So I'm genuinely curious what the threshold is for cpu temps, as in, what should be considered the 'red' zone.
I ask because recently while playing some EQ2 I would get short 3 or 4 minute stretches of incredible framerate loss. After some extensive testing and banging my head against my keyboard I finally noticed that during those periods of performance loss my CPU was getting throttled to 50% of the max frequency, which of course was choking out performance (especially since EQ2 is so cpu intensive).
So I installed CPUID I watched my temps while running the game. When the CPU was throttled, the temp would show a sharp decrease, then slowly start climbing again after my framerate returned to normal.

I'm guessing it's either a function of Windows 7 which is causing the throttle or a BIOS setting in order to allow the CPU to cool.
The temp capped at around 81 C. Is this an ugly temp? I'm half tempted to try and track down the setting and disable it but of course I don't want to cook my PC.

It just feels to me like 80C or so can't be THAT bad, can it?

You're probably getting a bad thermal reading. The only accurate tool I've found for reading Core i7 internal temperature is Realtemp. If your CPU is thermal throttling it's probably hitting 100.

 

[Rookie92]

O.K. if anyone still wants to help me solve this problem im getting close! I chatted a bit with guys on G skill forums too and i got to really looking closely at my voltages with and with out XMP. I seem to have 2 "Vcore" Values, and i dont know what they are for. One is "CPU Vcore" and actually goes down from 1.1375 to 1.03125 when XMP is enabled, the other is just "Vcore" and goes up from 1.088 to 1.248 when XMP is enabled, but i cant seem to adjust that. It's all very strange, I took pictures of these Voltage values and posted them below so ppl can see and maybe offer advice, both pictures are my BIOS valuse with XMP enabled.

This one shows the un-adjustable V-core in my "Motherboard Intelligent Tweaker" main menu
http://img706.imageshack.us/i/image0083u.jpg/


This one shows my adjustable "CPU Vcore" in Voltage settings
http://img823.imageshack.us/i/image0084.jpg/

I couldnt manage to change my Vcore so i figured it must be a problem with my CPU Vcore, i have a feeling the "Vcore" one may just be a reading of Volts somehow derived from "CPU Vcore". I couldn't understand why turning on XMP and slightly oc'ing my cpu would cause a decrease in the CPU Vcore like it did, so i turned CPU Vcore off auto and set it to its voltage without XMP (1.1375) When i did this and turned XMP on the Vcore that i couldnt change remained at 1.12 (previously it would go to 1.248 with XMP on) and the temps went down, they were around 80 at full load and 50 at idle! Which is a huge difference but not quite enough. Im wondering if you could help me build on this development to get it to run cooler again? I'm confused because temps went DOWN by increasing my CPU Vcore but thats backwards isnt it? So i dont know if i should increase again or decrease slightly for cooler system. Help would be great! Thanks

 

[wolfram23]

Sounds like the XMP just doesn't quite know how to adjust settings for your specific mobo. I like XMP to an extent but it's pretty much always best to find out the exact voltages you need manually. Also, when XMP is enabled many BIOSes disable most of the manual adjustments. My MSI didn't but my ASUS does.

Looks like you have CPU Vcore and then PCH Vcore. I've never seen it called that before but basically CPU Vcore is, obviously, for the CPU and it needs more for higher clocks. The PCH is actually for the south bridge and shouldn't need to be adjusted almost ever. The two main ones for higher CPU speeds are Vcore and Vtt. I think possibly the XMP is somehow just reading "Vcore" and changing both Vcore values even tho the only one that needs it is CPU and not PCH.

Again, try setting it manually to 160 bclk, 1600mhz CL8 RAM. Try keeping everything except DRAM voltage at stock and do some stability tests. If it's stable and temps are ok then you're good to go. If temps are ok but not stable, raise Vtt 0.01V and try again. After about 0.05V Vtt raises if it's still not stable, raise Vcore the same way... if you get it stable while raising Vcore you can try lowering Vtt again and vise versa.
If temps are too high, IMO just back off to 140 bclk run 20x with turbo and all the power saving features and run the RAM at 1400 CL7 1.6V (or 1.65V).

 

[Rookie92]

System stability seems good its just my temperatures could do with being 10 degrees less! It sounds like alot but considering i got more then a 10 degree decrease in temps just by leaving a setting on auto to see what happened maybe with some know how it is possible to get them down another 10. I think my PCH voltages have remained the same with and without XMP but i couldnt be 100% sure. Do you think i should try and decrease my Vcore a little and see how stable it is and see if temps go down? Even though my previous temp drop was actually due to an increase in CPU Vcore... Thanks

 

[wolfram23]

Sorry, I realise now I misunderstood what I was seeing. After thinking about it here's what I've concluded:
1) the screen where you can adjust all the voltages is your OC screen. Changes made here do not take effect until AFTER you Save and Exit the BIOS. This includes loading XMP... so to see what changes XMP makes, enable, save, exit (reboots) then go back to BIOS

2) the screen which shows only Vcore looks like a monitoring screen. This shows the actual current value. It won't change to what you set in the OC screen till after you save and exit.

If that is what you've been doing (save and exit before checking "changes") then I really can't make heads or tails of it, but I think you probably weren't... maybe... lol

 

[Rookie92]

lol! Unfortunately things are never that simple, as i was saving and exiting , I've tried increasing, decreasing Vcore and Vtt, but now they all stay around 80 under load which is still too high It confuses me aswell, but i suppose its only stock cooling anyway and i never expected to do any oc'ing. I went to the intel support site and went on a live chat, was referred to a list of XMP supported mobo/ram/cpu combos of which there were.... 5 for the i5 750 lol. Evidently my setup wasnt there. So i'll probly just reduce the timings and maybe bump the BCLK to 140 if im feeling adventurous anytime soon, but for the minute im tired of my BIOS!! Thanks a million for all your help mate, appreciate it

 

[Rookie92]

P.S. Still no sign of a "select as best answer" button!