Is my PC actually using all 12gbs of RAM or only 8gbs?

Hey everybody,

I just upgraded my RAM from 8gb to 12gb thanks to an awesome Notebook Review Forum Member sending me 4gb for free!! Thanks again!

The new RAM is a different brand then my old ram so I put both of my RAM sticks under the keyboard slot since I was told that they have to be the same brand in order to use dual-channel and the new one in the easily accessible spot.

Now to my concerns, yesterday when I was looking at HWiNFO, it said the memory size was only 8gbs and today its now back to showing the full 12gbs. Any idea why? It is possible to use the dual-channel when I only have 2 4gbs sticks together and 1 4gbs stick by itself, right? Or do I have to have both parts working in dual-channel?

Another just off-topic-ish question, what should my temps be around for my 7970M while gaming? I just play World of Warcraft/League of Legends. It just sounds like my computer has been having to turn the fans up really loud lately (yes I have cleaned it out, dusted, etc.), this is without a cooler just on my desk.

Thanks in advance for any help you guys can give me!

 

I think for dual channel you need to use either 2 or 4 slots. So 3 slots may be running in only single channel. Also remember that if the speed and timings of the new module are not the same as your other 2, all the sticks will default to the lowest speed module.
As for your 7970m anything is safe under 90c. The fans will always turn up high while gaming, no escaping that unfortunately. I have my fans blast to full speed during any game except torchlight 2

 

My 12GB (3x4) run in a kind of hybrid dual-channel thing. 8GB run in dual-channel with the third dimm running single channel with some kind of dual-channel gimmick speed thing. If I use only 2x4 i get barely slightly higher memspeeds than 3x4, but they're still upwards of 16GB/s bandwidth. Afaik you're using 2x4 and 2x2, right? if you paired them correctly they should be 12gb dual-channel.

 

Just out of interest, what speed was the free module? - if it's less than 1600mhz that you have in your signature, then ALL of your ram will run at the lower speed.

As for the dual channel/single channel thing, it's what Intel calls "Flex Mode" - basically, their way of running asymmetrical modules (not matched or symmetrical) to the best of their ability. You'll find a good thread on it here: http://forum.notebookreview.com/har...s/709895-12gb-ddr3-dual-channel-possible.html

For the gpu temp question, yeah....anything below 90c is okay - better if it's not often that high. I'd say a good "safe range" would be between 75c-85c under load.....when it starts creeping up to 90c, I'd be thinking its getting a tad too hot and you wouldn't want to run it at that temperature for long periods due to deterioration of the gpu itself.

 

Thanks so much for the replies,

They are all 1600mhz, HWiNFO shows that its dual channel so i guess it is running in the Flex Mode. It is one 4gb stick by itself and then 2x4gb sticks. I'm guessing it would be better if that solo stick was 2x2gb sticks but I got it for free so hey. So does having the extra memory over ride the fact that it has to run in Flex Mode? Or is memory speed better?

Thanks again!

 

Does more in flex override less in dual? Oh boy is that a can of worms. Well if in your case you ever need more than 8GBs then yes. Even single channel far exceeds any hit to the drive, even the fastest SSD. If you never exceed 8GB then that is where people differ. I say it does not hurt because the flex uses the paired 1st so it will function just like the 8GB of matched. Others seem to worry that for some reason the RAM used will be from the slower unmatched(single) 4GB. That is not supposed to happen the matched is used 1st and what kicks to the last 4GB would end up in the pagefile.

So in my opinion while it might not help and depending what you do, it really might not help. Using more than 8GB can be a challenge for most. And gaming is not that challenge. I do not, I repeat do not see it hurting in anyway.

Running benchmarks for the bandwidth is likely the most inaccurate measure of real world performance. The synthetic will test across the installed RAM thereby including the single channel and the penalty. In the real world the application/applications will frontload into the paired (dual) 1st then fill the unpaired (single). The benchmarks failure is why we still have this silly discussion of is it bad to have more RAM if some is unmatched.

While you or I are unlikely to solve the worlds ills with our computers. I would put my money on either of us before a benchmark, Memory even more so.

 

This ^ ^

+1 Rep for the input. This is pretty much what I was gonna say. Just try matching them so that they work better and the 7970m is ok as long as the temps are below that.