Worth buying an 1866MHz SODIMM kit for a laptop with i7-3740QM CPU?

[ayqazi]

Hi,

I'm about to get a Clevo laptop with a i7-3740QM, and I'm going to upgrade the RAM myself. Is it worth getting a Corsair SODIMM 1866MHz kit or a 1600MHz kit, considering they're both the same price over at good ol' Scan? The point is, will the 1866MHz kit run at 1866MHz with that CPU, or will it at least run at the same timings as the 1600MHz kit if runs at 1600MHz?

Thanks

[kompukare]

Can't give you a 100% on how it will behave (the BIOS of the laptop will decide, surely?), but unless you're going to be using the onboard HD4000 memory speed will make somewhere between 0% and 3% difference. And DDR3 1866Mhz might use more power or even run at a higher voltage.

[ayqazi]

I'm buying the Clevo P170em from pcspecialist.co.uk (otherwise known as the 'Vortex III'), if that helps.

[Bonebreaker777]

Unless you can overclock in your laptop the memory, the RAMs you would like to purchase would work at 1600Mhz, default thanks to the CPU. If you buy the higher rated memory modules they will just be clocked back to 1600Mhz with corresponding timings thanks to the JEDEC standard.

Make sure first that you can adjust the memory speed settings. If not, let the price decide. If the 1866Mhz modules cost virtually the same, might as well go with them. You could end up with lower timings with the 1866Mhz kit but I doubt that.

[ayqazi]

Unless you can overclock in your laptop the memory, the RAMs you would like to purchase would work at 1600Mhz, default thanks to the CPU. If you buy the higher rated memory modules they will just be clocked back to 1600Mhz with corresponding timings thanks to the JEDEC standard.

Make sure first that you can adjust the memory speed settings. If not, let the price decide. If the 1866Mhz modules cost virtually the same, might as well go with them. You could end up with lower timings with the 1866Mhz kit but I doubt that.

Hmm, thanks guys. I'll ask if RAM can be OCed before I proceed with the 1866MHz purchase.

Thanks

[ayqazi]

UPDATE: According to the official Corsair info, and this review: http://www.legitreviews.com/article/1932/

the memory runs at 1866MHz speed without any actions on the part of the user on any laptop, and in the review's case with a i7-3720QM which is similar to the CPU I want in my new laptop; is this correct? It seems too good to be true... I'm not sure what Corsair are doing but the RAM seems to get run at 1866MHz even though the max bus speed of the CPU is 1600MHz.

What's going on here? I'm going to go ahead and order the RAM, as it seems to work.

SECOND UPDATE: The NewEgg reviews here: http://www.newegg.com/Product/Produc...82E16820233243 seem to indicate that this is very laptop dependant - it seems to work fine in Asus laptops, but not so good in others... Corsair are obviously doing something funny to make the RAM run faster than the CPU's official support, it must be messing things up unless the laptop supports it. I wish I could get some elaboration from someone at Corsair

[Bonebreaker777]

Couldn't you browse for some Clevo owner feedback / forum? You couldn't be the only one with this.

Worst case scenario, ask the retailer, in case of a purchase of the unsupported memory modules, is he willing you issue partial refund and the other memory modules? With that option you would have the chance to try out the memory modules you are interested in and if they don't work out, you could always fall back to the officially supported ones.

Good luck!

[ayqazi]

I've confirmed from a Clevo owner that these don't work with 3rd generation Core CPUs - for some reason, the auto-overclocking magic only works on 2nd generation (Sandy Bridge) Core CPUs. Whatever tricks they're pulling to make them run at 1866MHz obviously aren't compatible with the memory controllers in Ivy Bridge CPUs.

[Bonebreaker777]

Ahh. Sad. Good luck choosing then a regular 1600Mhz kit.