Sandy bridge refresh question

Hi all,

Actually very happy with my M17x R3 (specs in sig), I was wondering what were the real differences between same line cpu.
I want to push my computer only for benchmarks,as my 2820qm can play nearly all games in high/ultra details.

I know the 2860qm can clock slighter higher than my 2820qm, the 2920xm has free multiplicator (trying to order one on ebay) etc ...

But what is the physical difference between those 3 ? More transistors ? Specific materials ? quality settings ?

Thanks for your lights

 

Processors that don't pass the stress test for the highest end CPU get binned into lower ranged CPUs until they pass the stress test. Example:

2920XM stress test: Fail? (overheat maybe, some L3 cache might not work, etc.)
2820QM stress test: Fail?
2720QM stress test: Fail?
2630QM stress test: Fail?

Discard.

I'm inclined to believe that they batch produce CPUs and see which ones meet the standards for which "lines", and sell them as that "line". In the above example there is a TDP difference between the XM and the QM, so it's not purely accurate, just a general idea.

 

Processors of the same type are all produced together then go through a step called binning. You can look it up on google, but basically each CPU goes through multiple tests and gets it's model number based on what test it passes or fails. One thing to note is that the m17x-r3 doesn't have the chipset required to use the unlocked multipliers on the 2920/2960xm.

Intel might also disable some features on some cpus like some virtualization tech on the 2720qm is missing on the 2630qm.

 

Sure they do. Multiple people in the m17x forums are using 2920/2960's OC'ed to 4+ghz

i might buy one too

 

My advice to you, is to get a 2920xm and overclock it to 4+ ghz for max benchmarks. There were some 2920 ES versions from Shirley (ebay) that were going for less than $326 shipped.

Intel i7 mobile CPU i7 2920xm ES 2.4Ghz | eBay

These are completely unlocked and will overclock to 4ghz

The Intel Xtreme Tuning Utility (XTU) will become your friend. In fact, i use it on my 2820 for max turbo. The multiplier is locked on your 2820, but if you increase your max turbo tdp to 55+ watts, you will get advertised max turbo speeds forever

by design once the short turbo time interval is over, the tdp is dropped to 45w on your 2820qm...and with that, your speeds will also drop to ~2.8ghz when all 4 cores are maxed 100%

if you have overclocking questions, post this in the alienware m17x forums. We've got some hardcore people there.

Here is a thread on XM overclocking on the m17x R3

guide-overclocking-2920xm-2960xm-cpus-m17x-r3-without-modded-bios.html

 

Oops, my bad. I thought i remembered seeing that somewhere, but i guess that's what i get or not doing my research.

 

Thanks so much for all that information + rep

 

Dell just doesn't want to ruin m18x sales by stating "temperature regulations" as an excuse to not sell XM's on the m17x-R3. In reality, Alienware kept the BIOS options on the m17x's anyways in-case customers they knew would get one aftermarket anyways.