GA-H55-USB3 CPU temp is high because of my DDR3?

[shadowillusion]

My Mobo: Gigabyte H55-USB3

My CPU: Intel i5-750

My DDR3: Corsair Dominator TR3x6G-1600C8D which has 1600mhz when XtremeMemoryProfile enabled...

Some thoughts, correct me if I wrong:
- i5-750 default memory controller speed is 1333mhz... So my gigabyte mobo must tweak it to 1600mhz...
- when I enable XtremeMemoryProfile (1600 mhz 8-8-8-24), my CPU VCore is 1.28V (idle) to 1.264v (100% load), temp is 56C (idle) to 99C (100% load)
- when I disable it (1333 mhz 9-9-9-24), my CPU VCore is 0.88V (idle at 1.2Ghz) to 1.184v (100% load), temp is 40C (idle) to 78C (100% load)

Some facts:
- I already reseated my CPU, even replace my CPU and motherboard with the new one from the shop, still the same temp
- 6 fan cooled case. No problem with the case
- Fan maxed out at 2500RPM++. No problem with the fan
- Stock fan, stock paste, stock frequency no OC

Question:
1. Is that temp when XMP disabled (40C (idle) to 78C (100% load)) is normal? If not, do you know why and how to solve it??
2. Is that temp when XMP enabled (56C (idle) to 99C (100% load)) is normal? If not, do you know why and how to solve it?
3. Do you think that I need undervolting? If yes, how?
4. Do you think that I need another solution (such as maybe kick-ass hydrogene cooling? )? If yes, please mention?

[onemilimeter]

Hi... you may always set the VCORE to a lower value manually (e.g. 1.0V). For my i7 920 and X58A-UD3R, I set the VCORE to 1.1V.

[shadowillusion]

if something goes wrong and the system wont boot up, how to reset the BIOS?

[onemilimeter]

I think it should be quite safe. For example, when I got my O/C setting wrong the BIOS will always be reverted to it's default factory settings.

Plus, according to the manual of your motherboard, it supports DualBIOS.

Plus, you can always reset the CMOS to default factory settings as follows:

[Dark Mantis]

First thing to do is ditch the stock fan and get a decent aftermarket cooler.This will make the biggest difference for the outlay but don't skimp get something thst is known to do the job like one of the new Noctua series or Megahalem etc.

[shadowillusion]

okay guys this is what I do... Basically I tried to attained XMP-like profiles while undervolting the VCore through manual setting

- disabling XMP profile
- upping BLCK from 133 to 160 (CPU OC'ed from 2.66 to 3.3Ghz, memory upped from 1333 to 1600Mhz)
- set memory timings from 9-9-9-24 to 8-8-8-24
- set DRAM from 1.5v to 1.64v (no 1.65v, only 1.64 and 1.66 in between)
- set VCore from 1.28v to 1.175v

Result:
50C idle to 85C max load

Question:
1. still think that 50C ~ 85C is not normal even for a stock cooler... what do you think?
2. which dram voltage would you prefer between these two... in BIOS it's only 1.64v and 1.66v while Corsair recommends 1.65v
3. Is there any other voltage/frequency recommendation in order to get a cooler system? Maybe multiplier from 20x to 17x (back to 2.67ghz then lowering the VCore?)

thanks for your attention. really appreciate it

[Dark Mantis]

Your temperatures are not unusual for a stock cooler. And you should NEVER overclock with a stock cooler.

[onemilimeter]

Better not to exceed the 1.65V limit.
You may try to lower the VCORE some more...
Or, like Dark Mantis suggested, try to get an aftermarket CPU cooler...

[Peteruk]

Just use the XMP settings stock cooler is not that good but hey maybe its just not clipped down properly.  

[Dark Mantis]

Just use the XMP settings stock cooler is not that good but hey maybe its just not clipped down properly.  

Yes very common problem.

[shadowillusion]

Thanks

next additional question:
1. Aftermarket cooler that you recommends... Please?

2. I would like to know the healthy temperature for i5-750... I thought going for 85C in 24h x 7w is not healthy... right or not? TCase spec for intel i5-750 (based on intel website) is 72.7C... Is that means that going more than 72.7C leads to damaged CPU?

And from prev post:
- That DRAM (1.64 or 1.66? both of them seems works)... I will perform memtest later... Now I'm still doing Prime95 to check whether this voltage is stable

Sorry for bothering you

Now I'm trying to lower VCore again... 1.175v is stable... Last time 1.15v wont boot up... I'll try 1.16v... Going to reboot now :p

Just use the XMP settings stock cooler is not that good but hey maybe its just not clipped down properly.  

That's the problem... If I applied XMP, CPU OC'ed from 2.66 to 3.2Ghz, the VCore is 1.28v and it makes my CPU reach 99C... That's why I tried to undervolt it

[onemilimeter]

By the way how do you get the "CPU temperature"? I'm not sure the CPU temperature given by software like RealTemp is the temperature of the CPU core or the CPU case. The temperature of the CPU core can be higher than CPU case.

I'm using Titan Fenrir v2 + Scythe GentleTyphoon

[Dark Mantis]

Maybe he's using Coretemp or something similar.

[onemilimeter]

If he's using Core Temp:

The temperature readings are very accurate as the data is collected from a Digital Thermal Sensor (or DTS) which is located in each individual processing core, near the hottest part. This sensor is digital, which means it doesn't rely on an external circuit located on the motherboard to report temperature, its value is stored in a special register in the processor so any software can access and read it. This eliminates any inaccuracy that can be caused by external motherboard circuits and sensors and then different types of programs trying to read those sensors.

[shadowillusion]

I'm using RealTemp (just google it)... It doesn't measure single CPU temp, but all 4 CPU Core temp is given... It's the same reading through my BIOS status monitor...

Finally guys, I managed to enable XMP (practically) while still maintaining the temp below TCase (72.7C)...

- disabling XMP profile
- increase BLCK from 133 to 160 (CPU OC'ed from 2.66 to 3.3Ghz, memory upped from 1333 to 1600Mhz)
- set memory timings from 9-9-9-24 to 8-8-8-24
- increase DRAM from 1.5v to 1.64v (no 1.65v, only 1.64 and 1.66 in between)
- increase QPI Voltage from 1.1v to 1.21v
- decrease VCore from 1.28v to 1.040v >> Undervolting leads to much cooler temp...

And as the result, my max load temp is only 72C! Before this, XMP enabled means 99C and my CPU throttled...

I'm using Prime95 as a CPU stability test... It's stable now

Thank you guys... You really helps