ABud

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Hi,

I built my first PC yesterday (scary stuff :lol:) and have been looking into overclocking it. Specs are:

i5-760
ThermalTake Contac 29 CPU fan
Gigabyte P55A-UD4
Corsair XMS DDR3 4GB (2000hmz) RAM
CoolerMaster Slient Pro M 700W PSU
CoolerMaster CM690 II case
Windows 7 64bit

Think thats all that matters!

With the CPU at stock (2.8ghz) it idles at 17C which seems good, yet when running Prime95 In-place large FFTs with 4 threads it heats up to 88C. This seems way too high and has stopped me changing the clock speeds. Does this mean I've not got the CPU fan on properly/ too much thermal paste or something else?

Also, my RAM is only running at 1333Mhz, is that a straight forward change in the BIOS to get it up to 2000Mhz?


Thanks for any help, and be kind :eek:


Andy
 
The 17C is wrong. When C States are enabled (specifically C6) it can cause wrong readings due to the shutting off/gating of cores. It's probably in reality around mid 30s... but anyway... Yes 88C is too hot. The max is 72.7C.

First off, pretty sure you just installed the heat sink wrong. Could be not enough pressure, could be not enough (or too much) paste. Definitely redo it. Just put a small blob of paste in the middle (after cleaning the old stuff off - alcohol is great for cleaning). Make sure there's not particles (like if you used kleenex, might leave little bits of paper). Then install the heat sink and screw it down with even pressure - so do one screw halfway, then the opposite one, then the next two, and so on until they're all in firmly.

To get the RAM up to 2000mhz will require you to have at the minimum a 200mhz base clock - which is a big OC. Of course you can reduce the multiplier so the CPU is less than 4ghz. However, that RAM can run just as fast at lower speeds by lowering the timings. If it's 2000mhz CL 9 (ie: 9-9-9-27) then you could run 1800 CL8, 1600 CL7, 1400 CL6 etc at the same voltage (1.65V I hope, it's the standard but also the max by Intel spec).

First get those CPU temps down (at stock speeds should be 50C give or take). Then maybe try 160 base clock (1600mhz RAM)... test it out. Intel Burn Test, Prime95, LinX, OCCT are all stress testers.

Aside from that, there's a lot of guides out there so definitely start reading up.
Here's a start http://www.tomshardware.com/forum/256144-29-1156-core-overclocking-guide
 

ABud

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I agree about the thermal paste, i think I've been a bit heavy handed with it! I'll redo that tomorrow and then work on the OC. Thanks for that link, the more stuff I can read the better.
 

mattimeo005

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Be careful when screwing your heatsink down, and don't screw it down too tight. Doing so can bend the pins of the socket, and can cause instabilities.
 

travisbundo

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I5 760 seems to run fairly cool. Full load on Prime95 and the cores average about 31-33 degrees. Never seen them go over 37 or even stay above 35 for more than a few seconds.
 
That seems a little too cool. What are your idle temps and ambient temps, as well as your cooling device? Remember, if the idle temps go below ambient or the temperature delta is very small, it is not possible (or unconventional cooling).
 

mattimeo005

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Yeah, that seems to be too cool. I'm using CM Hyper 212+ in dual fan setup, with AS5 and I'm getting around 29-34C, depending on core, for my idle temps, and P95 max temps around 49C. Not sure about ambient temps, but they are a very comfortable "room temp", in the range of 25C.
 

travisbundo

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Not sure what my idle temps are and if they're correct. Wolf said earlier that the readings are generally incorrect due to the cores not necessarily being on. When I go from normal load to full load on Prime95 I dont see much of a temp increase. The fan on the 212 goes from around 600 RPM to around 1800 and the temps might increase 5 degrees. When the load is empty Prime95 reads like 7c for all 4 core temps but like stated above that is likely incorrect.

What temp is the ambient temp on Prime95?

Cooling device, I use the Hyper 212 with the thermal that comes with it which is supposely not the greatest paste.
 

travisbundo

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What are you guys using for a case and whats the airflow like in it.

Not sure if Ambient = room temp but room temp is around 65 degrees farenheit.
 
Pretty chilly room temp then, which helps.

When running P95, are you sure you're running 4 threads not just 1? That would make a huge difference. Below 40C load temp seems way too low, mid 40s would be more reasonable... but, maybe you just got some crazy super chip?
 

travisbundo

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Yes it is all 4 cores for sure, cores 1 and 3 tend to be a bit hotter. I'm not a prime95 expert but I'm running the one that tests test the CPU the most. Idle temp without prime95 running is 3-5c. This probably is not accurate because most the cores are probably turned off. I turn on P95 and temp within first 30 seconds is around 20c. 37 peak, never stay there, 33c on average. I have GPU, Temp1, Temp2, Temp3, Temp, CPU0, CPU1, CPU2, and CPU3. GPU gets pretty hot, shows a flame usually. Temp1 and Temp2 generally stay around 25c idle and around 35c full load with blue down arrows. Temp3 idle temp is odd, it reads 5c. Temp is also odd it reads -128c. Cores0-4 are showing between 0 and 2c atm idle and will never excede 37c
 

travisbundo

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Full load voltages read in SpeedFan as
Vcore1 1.15v
Vcore2 1.58v
+3.3v 3.39v
+5v 5.03v
+12v 10.69v
-12v -1.17v
-5v -6.41v
+5v 3.60v
Vbat 3.10v
 
Hmm, that is a bit odd. My i5 750 downclocks and shuts down cores, however it never seems to lose the core temps at idle. Have you tried HWMonitor for monitoring temps/voltages before?
 

travisbundo

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No I have not used that. I use Prime95 and Speedfan, it's not showing those cores shutting off or the temps but it is showing them being borderline freezing. 0-3c and it does show these temps dropping gradually once Prime95 is turned off. 5-10c a second drop generally.

Just ran Prime95 Full load all 4 cores for 3 hours and results were the same. Nothing over 35c.

My case does have excellent air flow but I dont think it would make that much of a difference from the others.

At these temps whats the estimated OC I could reach with the 212? 4.0?
I was planning on going 3.6 but if these temps are exceptional and 4.0 is reasonable without putting my CPU at too much of a risk, Id go that route.
 
3.6 is easy on an i5, and 4 is quite doable if you are willing to increase voltage. For comparision, my i5 750 (essentially identical) could do 3.6 GHz at 1.15V and core temps would top out at 58-60C.

And on second thought, I haven't run my i5 at stock in ages, so 35-40C on the cores may be reasonable (especially with that low ambient temp). Obviously though the idle is off (your ambient is about 18C) which is odd.
 

travisbundo

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I'll probably stick with 3.6 then. Also need to get my RAM from 1333 to 1600. Been a bit shy to try to OC yet. It seems pretty straight forward but jsut got the PC put together last week.
 
It's pretty easy to set the base clock at 160 and let her rip. You can even leave the voltages on auto - I found that worked up to around 170 base clock. However, it's good to manually adjust them to just make sure they're as low as possible while maintaining stability. At 160, the RAM will be at 1600mhz and just set the DRAM voltage and timings according to the manufacturer specs and basically you should be fine. Obviously stress test it to check temps and stability but all in all it's pretty easy. Works with Turbo Boost as well, I might add. If you disable turbo, 4ghz should be attainable with just a little effort into voltage tweaking.
 

mattimeo005

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Like someone stated above, regarding your core temps, it's not possible to have temps lower than ambient. 65F is about 18C, so the absolute lowest you could go is that. It's much more likely to be higher than that by 5-10C, hence why you would expect your temps to be in the 25-35C range at idle. If you try different monitoring software, you might find one that shows the correct temps, but I suspect that they all read off from the same component, and so you would see the same reading regardless.

Either way, it's definitely an inaccurate reading, and so I wouldn't attempt to overclock until you get an accurate one, or else you could risk sending your cpu to the trash bin as you put 100C temps in it when you think you're only putting 70C.
 

travisbundo

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Not sure, several programs have read the same, the reason the ambient temp is so low because my computer physically cools the room temp down by about 10 degrees. The air blowing out of the exhaust is ice cold compared to the room temp air. The only exception is the GTX 470 exhaust which blows out very very hot.
 

mattimeo005

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But from a purely scientific stand point (second law of thermodynamics), it is impossible for air of a certain temperature to cool anything down below its own temp, unless there is evaporation or some other source removing heat from the system. So basically, since you would hope that you have no water in your system to evaporate, its not possible to cool below ambient temp. It might feel cooler to your hand, though, but that's only because your sweat is being evaporated from your hand when you go to feel the air flow. It's not actually cooler.