Which is better for RAM? Same brand but different speed or different brand but same speed?

which is better for ram? same brand different speed or different brand same speed? I mean I bought and Alienware 17 last 2014 and immediately upgraded the top RAM toCorsair Vengeance Performance 16GB (2x8GB) DDR3L 2133MHz CL11 Laptop Memory Kit (CMSX16GX3M2B2133C11) . Few Years after, I decided to upgrade the bottom two (behind the keyboard) and I can no longer find the same Corsair Vengeance 2133Mhz. So I settled for Corsair Vengeance Performance Memory Kit Unbuffered SODIMM 16GB (2x8GB) DDR3L 1866 DRAM CMSX16GX3M2C1866C11 1.35V . Is it okay that I'm using that RAM Set? or should I get a HyperX 16GB (Kit of 2) 2133MHz DDR3L CL11 1.35V SODIMM HyperX Impact Laptop Memory HX321LS11IB2K2/16 to match speeds with my older RAM Module?

 

Ideally the speed and brand should match. The most important thing though is that the speed and CL match. Otherwise your system will down clock the CL or speed to match the next available speed and CL supported by the RAM you have installed. With the 1866mhz set the faster RAM will have to downclock to at least 1866mhz or even 1600mhz if it doesn't have a 1866mhz profile. If your main use of the computer is gaming and you have a discrete video card you really won't notice a difference in framerate / performance with faster or slower ram. See this article. While Sky Lake and Kaby Lake are a bit different the chart on there still hold pretty well for when you should go for latency vs. speed.

 

With a platform I or my clients depend on; I always buy a new, identical full set of RAM and after testing for 24 hours or more; sell, donate or re-use the old SoDimm's in another system (as a matched set).

You may not have any issues running the configuration you're using now; but myself? I would buy another set of Corsair Vengeance Performance Memory Kit Unbuffered SODIMM 16GB (2x8GB) DDR3L 1866 DRAM CMSX16GX3M2C1866C11 1.35V and remove the old, slower RAM.

See:
http://forum.notebookreview.com/thr...ull-speed-help-screenshots-appreciate.699186/

Your system may not be able to use the latest RAM at it's indicated speed; but that doesn't mean it won't run faster with it either.

After replacing unmatched RAM modules with a matched set; I've experienced (many times) a more stable and reliable platform with random and unexplainable glitches minimized or gone entirely.

It's your call; but ime? A matched set of RAM = a more reliable, dependable and stable system.

 

If you want to go that route then you should also look at your laptop manual for the QVL for RAM and only buy from that for the best stability. As those modules are specifically tested for the motherboard to ensure compatibility and stability.

 

Hi there, @murixbob and @tilleroftheearth, thanks for the input, unfortunately I already bought the 1866Mhz Corsair and when I check my Ram speed with Speccy or CPU-Z, it shows 933Mhz, so I guess the 2133Mhz clocked down to accommodate the 1866Mhz.

Thanks very much for the advice and info, will try to buy again a set of 1866Mhz, its just a shame that I paid a lot for the 2133Mhz! Lol

Its been a little over 5 months and haven't had any issues with the RAM, I think. Games are doing okay and daily operations are smooth. Didn't even notice any difference from using a 24Gb Ram (Mixed also Corsair and Original Dell Alienware) to the Mixed Corsair 32gb.

Its just that I stumbled to my old post on TomsHardware Forum and I got a one liner reply and I thought maybe NBR could do better, and surely You guys didn't fail! Super Thanks!

 

Oh no! My apologies!

I mixed up my 'recommendations'!!!!

Of course; what I meant was to buy the fastest (matched) RAM you can and install into your sytem; yeah; the 1866 is slower.

(Sorry!).

 

Anytime. Also not sure if you did test the new ram, but I always run an overnight session of memtest86+ when I install new ram to ensure the RAM is stable and has no errors or issues on it. There is the original version from passmark and an older port available to boot from usb or cd.