STOCK Core i7 CPU comparisons??

Hi Peeps,


I just wanted to get your thoughts and expertise on the 820QM/840QM vs the 920XM or 940XM.
Comparing them in stock clocks and OC aside what exactly is the difference. Only a minimal higher stock clock and turbo boost value correct?

Where the extra $500 - $700 upgrade depending on which country your in mainly comes down to the fact that the XMs are unlocked and great to OC correct?

Also for comparison the core i7 720QM and i7 740QM chips are $400 - $600 dollars less than the i7 820/840QM CPUs. The main difference there is again slightly higher clockrate/turbo boost clock and an extra 2mb cache correct?

Would the 840 be that much better than the 740 just because of the cache? I just wanna get a better understanding and all your thoughts. Thanks!

Also in games and day to day tasks how much better would the say 840 perform compared to the 740?

I'm actually looking into upgrading to the 940XM someday in the future perhaps, however I just wanted to understand more and learn the basics 1st.



Cheers.

 

The Core i7-920XM and 940XM are Intel's first Extreme CPUs that are in a league of their own compared to other mobile quads. The 720QM/740QM/820QM/840QM don't compare.

When all 8 threads are fully loaded, you will get the 12 multiplier on a 720QM or the 13 multiplier on a 740QM or 820QM. Big deal. An XM CPU can be running this exact same load with a 26 multiplier across all 8 threads for a 100% boost in CPU performance. Once fully overclocked, there is no significant difference between the 920XM and 940XM so you might as well save some money and go with the 920XM.

The XM series have fully adjustable turbo multipliers and just as importantly, they have fully adjustable turbo TDP/TDC settings so even when fully loaded, these CPUs can be tweaked, with the help of ThrottleStop, to fully deliver the goods.

If money is tight then head to ebay and look for a 920XM ES. Shirley's is selling these for $380 at the moment.

New Intel® Core? i7-920XM Processor 2.0GHz/8m/1333 - eBay (item 250697286062 end time Oct-15-10 05:10:06 PDT)

After that you can dump your present CPU on ebay to cover the majority of this cost. Many users on NBR are running these and I haven't heard of any unhappy users yet.

 

Thanks for the ton of helpful info on the XM series. I didn't know that there was THAT much of a difference on these CPUs, and @ 380 itself that seems to be a bargain and a half. I take it there is further info in a wiki about maximizing these processors?

Actually you'll have to excuse me here. You said that all 4 cores (or 8) get that "turbo" boost?

according to: http://www.legitreviews.com/article/1084/1/ - its only 1 core that gets the full performance boost or 2 that get a semi boost.

Am I reading that article wrong? is the information old? or is that "not-optimized" as per some of the instructions you had posted?

And after further reading some more - it is your program that is doing the work in optimizing the CPUs to be fully utilized. Tell me my friend, does this work on non 9 series CPUS? (to prevent CPU throttle, not the turbo multiplier above the limits of the 9 series)

 

Throttle stop doesn't work to adjust the multiplier of the non-extreme CPUs. The reason it works for the 9 series is because the have the multipliers unlocked in thier programing. It does allow you to adjust the TDP though.

 

don't forget about cooling and battery/power........

 

it doesn't matter.. the M17x can easily take 3.33GHz on 8 Threads.. just that ur going to get a very noisy fan.. if ur going to get an extreme , it worth it.. just buy from ebay.. a OEM 920xm can be gotten for $600 if ur lucky... its not worth spending that much for an 840qm from dell if u can get a 920xm for that price urself.

 

I took uncleweb's advice regarding buying from Shirley and picked up a 920xm myself. this computer is definitely worth it.

 

not to spoil your party, but could you please do some benches/tests on these es cpus.
a couple of guys from the sager forum actually got themselves es 920xm's some months back (from shirleyfu nonetheless) but however found the cpu to be throttling at 76-78*c mark at stock clocks. other oem/retail 920xm's by comparison could maintain their stock or overclock well beyond these temps however. chinoboonic's o/c of 3.6ghz 4cores non-ht for example holds quite well even in these temps.
im interested myslef as i am contemplating a cpu upgrade v soon.

 

I wouldn't say its a party I'm having here. Just an average Joe looking for above average performance. I won't be overclocking the CPUs (at least not in initial plans) - but to have something run multi-core "turbo" speeds is something I would like to have.

 

ok. please do post some comments on how you find the es when you get it. thanks

 

I bought the 940XM ES from Shirley. The reason i went for the 940 instead of 920 is that it is essentially the same CPU but it is the second generation. Made me feel a bit safer. It is completely stable up to TJmax (100c) but i have settled for a max temp of 90c. I'm using Throttlestop to downclock the CPU whenever the temp reaches 90c. With stock cooling on my Asus G73 the CPU reaches multplier 26 when pulling 1 thread each from all 4 cores and multiplier 22 when 8 threads are pulled. Never had any problems with the ES CPU and it does not run hotter than the OEM version. And the difference between the 720QM and 940XM is BIG.

 

Cool thats a great little story you got there Chiefs.

Could you perhaps elaborate a little bit more about your experience in the performance increase area. Where you saw the most gains and jump in performance. Perhaps in which games how so or in other programs/applications? Much Appreciated.

Just trying to get a better feel for the overall performance boost and stock setting usage increase in performance.

Cheers.

 

thats good to know indeed.
the 940 es'es could be better than the 1st gen 920's.
i tried pm'ing soviet sunrise but he didnt want to comment further on the tests he did with the 920 es.
from what i remember they were experiencing throttling issues at 78-80 or even lower. they all returned their cpu's.
ill have a look a shirleystore for sure

 

My experience with the 940XM at stock speed is: Booting up Windows, opening IE, downloading Throttlestop and... there it ends. Sorry
I am not trying to be rude but, the whole idea with an Extreme CPU with unlocked multipliers and TDC/TDP settings is to, not run it at stock settings. Leaving the TDC/TDP values at Intels default and just raising the multipliers gives quite a boost with a minimal increase in temperature. If you want me to do some testing/benchmarking, tell me what you are interested in.

Here is some benchmarks at stock speed.

Review Intel Core i7-Quad "Clarksfield" CPU Refresh - Notebookcheck.net Reviews

 

imho the stock clocks of the 940xm are good enough, but the o/c ability gives it a bit of flexibility and futureproofing.

i would be more interested in realworld benchmarks. if you have some adobe prgrams, it would be interesting to see the following: render and ram preview speed in AFTER EFFECTS; encoding speed in PREMIERE PRO; hdr pro and photomerge speeds in PHOTOSHOP.
also, did it help in the snappiness of your computer in general?

 

can you underclock/overclock the 920/940xm's on the fly or does it require a reboot?

 

its on the fly.
you can even tell it to use max clocks but not force it... so if the temps go too high, it will auto down-clock. TS also has it's own settings so you can set it to different profiles if the temp goes high as well.

in terms of encoding performance, i've noticed at least 4x the performance of my old 720qm. what used to take all night, is now about an hour task.

in terms of gaming, not much is gained.

the power is in the multitasking. having 4 cores at 3.2ghz is just godly atm for a laptop. if you can handle the temps (m17x r2 can - heck my m15x can) then you're good to go.

in terms of benching, the only synth bench i've tried was wprime, getting around 7.5 sec best time for 32m.

 

4 x encoding. thats godly in itself.
i can also see myself surfing and such while rendering/encoding in the background.

on the fly is awesome, so i could downclock this to 840qm levels if i wanted to (i only have a 120watt psu) and crank it up when the power is needed.

 

I dont have Photoshop but i am using Digital Photo Professional for my Canon 50D a lot. When decoding RAW images, applying filters, converting images etc it is about twice the speed of the 720QM.

Correct! If you are using Throttlestop.

 

I am pondering an xm. How is your heat/noise?

Is it safe to think that I could set the CPU to run at 2.8 for 8 threads assuming I get a good sample? That would be superb.