2920XM or 3720QM for M17x R4

My friend has got an opportunity to purchase a 2920XM QS (D2 stepping) for less than $150.

His M17x R4 has a 3720QM.

I told him that he should go for the 2920XM QS, as it has much better potential in oc.
What do you guys think?
Am I making the right recommendation?

TIA

 

Personally, I'd go with the 2920XM. The 3720QM can be sold to make up the money as well.

Stock wise, the 3720QM will be faster. However overclocking the XM will be much easier and it will easily surpass the performance of the 3720QM.

 

He should overclock the 3720qm though to 3.8ghz on all cores and 4ghz on a single core which has no investment.

 

My impression is that 2920XM can easily go above 4GHz on all cores, I see this kind of feedback from almost all M17x R3 users.

Plus with some luck, he might be able to sell 3720QM for more than he has to pay for the 2920XM.

 

How the hell does the 2920XM work in a Ivy Bridge laptop? Do they use same socket??

 

Yes they both use the same socket.

 

I'm pretty sure they don't. When Mr. Fox had to upgrade his M18x R1, it required an R2 motherboard for him to replace his Sandy Bridge CPU with an Ivy Bridge CPU. I've never heard of someone going from Ivy Bridge to Sandy Bridge, lol.

@Tseng: The only upgrade "worth while" over the 3720QM is the 3940XM. But even with that, you may not be able to unleash it in the M17x R4, as the R4 wasn't designed for an XM CPU, but it will work. Usually people who upgrade to extreme edition CPU's plan to do some overclocking, and that's what I'm referring to when I say, "unleash it."

Other than that, I agree with Meaker.

 

+1 Not same socket

Motherboard would panic if you did manage to install it somehow. Would be best to run the highest overclock on the 3720QM or get the 3840QM if you find a decent offer.

 

M17x r4 and m18x r2 have backward compatible motherboards for some reason. I've seen people do it on here. Problem i see is the memory controllers and power consumption. more power draw on a sandy and sandybridge chips usually cant handle 1866 ram when ivys can usually do 1866+. 2133 definitely wont work on a sandybridge. either way they are great performers but i went with my 3820 for a reason.

 

ARK | Intel® Core

ARK | Intel® Core

Both sandy bridge and ivy bridge use the same socket....

A lot of desktop boards that came out with sandy bridge support ivy bridge with a bios update.

The m17x R4 and m18x R2 support both Ivy bridge and Sandy bridge CPUs. They both use socket PGA988 on the mobile platform.

The m17x r3 and m18x r1 do NOT support Ivy bridge CPUs however.

 

Hmm, well, it still doesn't make much sense to downgrade. Sandy Bridge also consumes much more power, at least from what I've read. If this is true, even with an unlocked Sandy Bridge CPU, you won't be able to overclock it as far to get much more performance out of it, ultimately making it a completely pointless "upgrade."

I've never owned Sandy Bridge or anything of that era (in gaming). I started out on Ivy Bridge, and sort of miss it.

 

Sandy bridge overclocks well. However, I do agree. Unless the OP's friend will be doing some serious overclocking/benchmarking, I'd stick with the 3720QM and turbo boost overclock it if any overclocking will be done.

 

Almost all ivy bridge notebooks will accept sandy processors but at 3.8ghz the ivy will outpace a sandy at 4ghz while being much more power efficient.

 

The HM77 mobo does support a SNB processor while HM67 mobo does not support an IVB processor. The only problem is, the CPU power is locked by the BIOS(at least for stock BIOS, I don't know if there's such limit for A11 unlocked) in M17X R4, for QM, it's 45W long-term and 56W short-term, for XM, it's 55W for long-term and 68W for short term, you can change the value and save it, and it looks take effect, but it does not take effect actually if you measure the power using stress test. Thus it means it has no enough power for 2920XM to overclocking, under high stress, a 2920XM is easily to get above 60W at stock clock(3.2 on all 4 cores), that means if the high stress exceeds 1 minute, 55W long-term power could not even maintain the stock clock for 2920XM on this model. However, even a 3610QM can stay at 3.1GHz on all four cores forever if you want because it is shown that it's lower than 45W all the time during the stress test. Thus, though 2920XM could be an upgrade over 3720QM on M18X R2, it's a downgrade on M17X R4 indeed, it can't even outperform a 3610QM with locked power limit. For a decent 3720QM, 56W is enough to maintain 3.8GHz all four cores, 45W can maintain about 3.4 to 3.5GHz all four cores, that means for a high stress program, 3720QM runs at 3.8GHz at the first 56s, after that, it will stay at 3.4 to 3.5GHz which is still good enough. If you want to upgrade your system, the right choice would be 3920XM or 3940XM, a 68W short-term power can push it to 4.2GHz all four cores during benching, 55W long-term makes it stay at 3.8-3.9GHz all four cores for real-world programs. The only thing you need to concern for 3940XM is temp, IB processor generally runs cooler than equally clocked SB under 3.7GHz and consumes much less power, while pushing it to a higher clock and reach the same power with a SB processor, it gets heated quicker. I would personally recommend you to stay with 3720QM which is good enough after you overclocked it.

 

From what I've tried, I would give an opposite opinion on the memory support, I've tried 6 SB processors (include 2760QM, 2820QM, 2860QM, 2960XM), 4 of them support 2133MHz all four dimms, the rest of them still support 2133 for 2 dimms or 1866 all four dimms. However, when I got a 3740QM at the first time, it could not even support 1866 for 2 dimms, had to work at 1600. And I was told by many people that IB mem controller is generally worse than SB for mobile Quad-Core. Fortunately, the 2nd 3740QM is nice, supposts 2133 all four dimms and has a low voltage that still stays cool after OC, while my previous 2960XM got overheated easily after OC.