mixing ram speeds

[ipaas]

hey!

i recently bought 2x8GB (corsair vengeance cmsx8gx3m1a1600c10) for my g75vw to swap out the pre-installed 2x4GB (hynix hmt351s6cfr8c-pb).

little that i knew, that the laptop had 2 extra memory slots available (bestbuy told me the laptop has only 2 slots and both are used). i didn't bother to research before opening the lid on the bottom. diving head-in i inserted the new memory modules and everything boot up nicely. windows 7 shows 24GB installed memory and that's that.

since the hynix modules operate at 800MHz, the corsair modules are limited to 800MHz as well.
my question is, what would be best performance-wise: having 24GB @800MHz or 16GB @1600MHz?

this memory combination occasionally freezes the laptop on boot.


thanks in advance!

[rewben]

since you're running the new ram with the existing stock ram, it should work nicely without problem, but most probably with a clock of 1333MHz instead of 1600MHz. as for the freezing part, i'm not sure about that.

yes, you should have 4 slots and to run mixed ram it's best to get a matching pair. you can read more here.

[bignazpwns]

You can mix ram all you want. I ran it and mixed it and i ran crap PNY 1333 ram at 1600mhz. With the VW you just dl the intel xtreme tuning utility and change the divider for the memory and bump the timings up on the 1333. On the VX the XTU dont work so pretty much sol unless you get a unlocked bios.

just a heads up messing with the timings and stuff can cause your system to lock up and fail to boot. You will need to remove the cmos batt under the kb. Best to but the good fast ram under the kb and the cheap stuff in the bottom so if it locks up you just pull the crap ram out turn it back on and it will boot. Then reset the settings and instal the ram again.

[Pitcher1]

i think when you use mix memory, the speed will follow low speed.

[bignazpwns]

Mike_Lu@ASUS wrote:
i think when you use mix memory, the speed will follow low speed.

It will unless you change the multi with intel XTU then you need to raise the memory timings so the 2 slower sticks can run stable at the higher speed since its not very common for 1333 ram to run at 1600 with the stock timings but i seen it done before.

[ipaas]

thanks for the replies!

for one reason or another the intel xtu don't show the memory tuning options.
but i'm still interested in if mixed 24GB @800MHz performs better or worse than unmixed 16GB @1600MHz?

thanks in advance!

[bignazpwns]

Do you have a G75VX? Seems that its not working with the VX. Could be a windows 8 issues or a issue with the VX.

You wont see a diff. in the ram unless you are doing car or photoshop and only because those programs will use more then 16gigs of ram if you let them not the speed. Ram speed means nothing unless you got a APU or a igp. Ram timing has a much better impact on preform then ram speed.

[ipaas]

i have g75vw on win7. i do use photoshop constantly and often for massive 1GB+ psd's, so far the performance have been outstanding.
but thanks, i just wanted to have the answer for my own doubts, i couldn't find much resources googling on the topic.

thanks again!