i7-840QM -> i7-940XM - temp difference stock and OC'ed.

Has anyone tried upgrading from 820/840QM to 920/940XM and can shed some light on heat/temp difference during normal and OC'ed operation?
I'm thinking of going that route but not sure if the stock cooling (no retention mods, just re-pasting) will keep the extreme CPU at bay.
Right now, my 840QM is hitting 75C @ max load during games and benches. Only Prime can push it above 80C.
How different would it be with 940XM?

Thanks

 

add another 10-15C on top of your 840QM temp. that's about it.

 

15C? Including OC'ing or just stock?

 

at stock it would not be much different on load temps.

however, unlocked and/or overclocked using throttlestop the temps can easily get out of control. i have the m15x so temps will be different, but i normally run my 920xm @ 25x with 96/88 tdp/tdc and the max i've seen is 88C (thats 100% load for over 4 hrs batch converting avi -> dvd with software capable of 8 threads)

i also set it to throttle the cpu back somewhat if it reaches 95 but afaik it hasn't happened with my current paste job.

 

about 90C for stock. using Throttlestop 82 TDP can easily hit 99-100C on wPrime.

 

Hmm..., if that's the case, I might abandon this idea. 840 performs on par with 920XM @stock. I only wanted to give it a go to have a few extra FPS in some CPU demanding games, but 90C+ is the deal breaker for me

 

the 840 is not on par with the 920 @ stock... close yes...is the difference noticeable not really...on par... no.

 

Same max turbo boost, and only 0.13ghz less when loading 4 cores.
I've seen quite a few reviews and also ran the same benches and games to say - it's more than close.

 

I think one of the benefits of having the XM cpu is that it's able to run turbo boost on all 4 cores compared to limited cores on the 840qm.

 

agreed, I have run 3.8GHz at least, on all four cores benching.

 

Yeah the 840 doesn't come close to 920xm/940xm. Those CPU's with unlocked TDP's easily hit desktop territory and in many cases beat desktop i7's.

 

I'm talking about stock performance, not OC'ed.
And that's a crazy frequency even for OC'ing, DR.

 

Because of AW's unique bios that allows all 4 cores to operate at the same multiplier, the extreme CPU's run at a higher frequency than they normally would in other notebooks. So even at stock they outrun a 840 easily. I hope the person that bought my system posts his impressions + benchmarks here. He bought it with all my mods in place with the 940xm.

 

lol, yea, not to mention I was running 130W TDP, and found that if I increase the pressure on the heatsink (going to put a copper shim in when I get home), I never thermal throttled. Granted it wasnt stable, but stable enough for benching, sometimes lol

 

Agreed with joker, you can almost run the XMs at twice the speed of the 8 series cpu's

 

Do the CPU retention mod, it will let you run very high TDP's on stock cooling. Just be very careful if you do it, one person killed his 940xm while trying it and destroyed his mainboard.

 

How'd he do that? What exactly is done? Because I've bent the heatsink, and still can't get enough pressure. Sucks benching when you have to hold the heatsink down. Especially when running longer benches my hands get tired. I was going to put a copper shim between the CPU die and heatsink when I get home in a few weeks.

 

Here's my thread on it: M17x-R2 Wikia Forum • View topic - Retention mod + more on CPU = great temps (at least for me)

I got excellent results with it.

 

Sounds good, bookmarking. Will gve it a read at work tommorrow and see if I can get the same results when I get home and get some time. Thanks again.

 

When 8 threads are fully loaded, the 720QM/740QM/820QM/840QM will give you zero turbo boost so you will be running at the default multiplier and that's it.

Code:

[B]Maximum Full Load Multiplier[/B]
720QM - 12.0
740QM - 13.0
820QM - 13.0
840QM - 14.0
920XM - 24.0
940XM - 25.0

To reach the maximum multiplier across all 8 threads you will have to raise the turbo TDP/TDC values using ThrottleStop but at least you have that option when using an Extreme CPU. The non-Extreme Core i7 CPUs don't have this option so once you exceed the turbo TDP/TDC limit, the junior quad processors don't give you any turbo boost.

When people start talking about a 100% increase in CPU performance, for once they are being 100% honest. If you increase the multipliers using ThrottleStop, you might even get more than a 100% increase in performance.

 

^^^^^^^^^^

 

Ehahahahah Junior quad core processors LOL.
Ah I can't wait to try an XM.

I'm not sure if its the higher clock processors or whether if its the lack of driver support. However running a game like FIFA11 on both my R1 and R2. The R1 plays and feels much smoother. With MSAA set to 4X the R1 smashes the R2 in frames. Like almost double.
However when MSAA is disabled the frames then are very close. Not too much difference between the 2 systems, however it feels and plays much more better on the R1. Specs in my sig except I am still currently running the X9000 CPU in the R1.

So my conclusion is the higher 2.8ghz as compared to my 740QM CPU clocks of 1.73Ghz might be the difference or otherwise it is just GPU drivers. I hope its just the GPU drivers though.

Also how much better is the 840QM compared to my 740QM? All I can see is a slightly higher clock increase and the 8mb cache as compared to the 6mb. + of course the $400 - $500 surcharge from Dell LOL.

Cheers.

 

PassMark CPU Lookup

PassMark - Intel Core i7 840QM @ 1.87GHz - Price performance comparison

PassMark CPU Lookup

PassMark - Intel Core i7 740QM @ 1.73GHz - Price performance comparison

227 points btwn 840qm and 740qm


920xm

PassMark CPU Lookup

PassMark - Intel Core i7 920XM @ 2.00GHz - Price performance comparison

PassMark - Intel Core i7 940XM @ 2.13GHz - Price performance comparison

CLIFF notes: SAVE YOUR $$$ for XM

 

The PassMark data might be based on the default i7-920XM setup where the turbo multipliers are all different. The way the Alienware M17x has the 920XM set to the 24 multiplier across the board might move it a long way up that chart towards the top.

 

^^^^^^ very true so at minimum you would expect the advertised score but if you are buying the 920xm it is for the OC capability and most folks around here run there chips all day at 25-27x multi and when i am benching i can set cores to 28-28-27-26 and push that sucker all the way up the passmark ladder and trump over the locked multiplier CPU...this is where it shines once you pair up a solid chip like the 920xm with Throttlestop...match made in heaven....THANKS UNCLEWEBB....l8r


Edit: From benching and all i learned my last core is a PANSY it don't like going over 26x multi and at 27x multi give's me a welcome BSOD suprise everytime lolz.

 

Thanks for the info, guys!
Will be surely looking for the extreme CPU.