Less RAM recognized than I have total

Toggle sidebar Toggle sidebar
S

Socardion

Reputable
Mar 10, 2014
3
0
4,510
Recently got a hold of some RAM sticks that a friend says don't work period in his rig. Noticed right off the bat that the 2 4GB sticks are clocked at 655MHz according to Speccy, which seems strangely low from my experience. W7 64-bit Ultimate SP1 also shows that I only have 4GB installed after a restart, where it previously displayed 8GB installed.
All my Motherboard drivers are up to date and my mobo supports 64GB of RAM, so that's not an issue.
Would love to hear any ideas as to what you all think the issue is as I'm lost.

EDIT: I'm using an APU. after a little looking it seems like that could be a factor, but I can't be sure.

Another Edit: The following is what Speccy is showing me.
Memory Usage 40 %
Total Physical 3.20 GB
Available Physical 1.89 GB
Total Virtual 6.39 GB
Available Virtual 4.78 GB

Would like to make it clear that the RAM is DDR3 and both have a normal 4096MB available according to my Mobo and Speccy, it is being used by windows differently however.

Clockrate issue has been solved, but the memory usage issue has not.
 
Sort by date Sort by votes
smorizio

smorizio

Titan
Jan 22, 2010
30,984
9
125,315
first off with cpu-z look at the ram spd info and memory info. make sure there close in voltage and speed to the ram you have now. if the ram old ram is 1333 ram and your ram you have is 1600 speed the mb has to slow down to the 1333 speed. also if the ram not in all the way it can be read/not read. also check your mb guild that the ram is slotted right banks.
 
Upvote 0 Downvote
photonboy

photonboy

Titan
Jun 20, 2006
21,567
13
85,015


THIS.
You also DOUBLE the performance with two sticks in Dual-Channel which may be why "1600MHz" memory is really is two 800MHz sticks together.

Don't quote me on that exactly, but I do know the actual reported speed of an individual stick is HALF of what's listed on the box.
 
Upvote 0 Downvote
S

Socardion

Reputable
Mar 10, 2014
3
0
4,510


Thanks for the post. I wasn't familliar with the difference in MHz and MT/s, this led me on a bit of an educational journey. Lol
 
Upvote 0 Downvote
CaedenV

CaedenV

Splendid
Jun 14, 2011
4,829
3
23,465
A few things about Photonboy's post:
1) double data rate (DDR) means that memory can send information on the up and down cycle of each clock. So take the clock and multiply by two to get your MT/s 665 would be essentially DDR 1333.
2) Dual Channel is the ability to run two sets of ram independently of each other. In theory (and in synthetic benchmarks) you would be able to double the performance... but in reality it is about a 15-30% performance boost. Still quite significant... but certainly no doubling in performance.
 
Upvote 0 Downvote
photonboy

photonboy

Titan
Jun 20, 2006
21,567
13
85,015


Yeah.
I tried to not get too technical because the last time I did some guy freaked on me like I shot his dog and kept hounding me even in other posts.

Anyway, if the OP wants more information about this here's two good links:

DDR: http://en.wikipedia.org/wiki/Double_data_rate

Dual-Channel: http://en.wikipedia.org/wiki/Dual-channel_architecture

Again though, what's important is that memory is often listed in software such as CPU-Z or whatever as HALF of the rated value (like 800MHz if it is 1600MHz memory).

I realize my post above was a little misleading. I believe it should be that the memory is noted in software as 800MHz as that is the SDR performance, but on the box for the memory it says 1600MHz because it would likely be used in DDR.

And Dual-Channel is just two sticks to double the communication speed between CPU and RAM (though as said real-world performance would be lower since the CPU likely would bottleneck this).

So...
1) 800MHz is SDR performance (what it reports in software often)
2) 1600MHz (what it says on the box) is DDR performance and how most motherboards use it
3) Dual-Channel is two sticks effectively DOUBLING the communication rate between CPU and System RAM
4) Real-World performance in Dual-Channel is often not much better that Single-Channel since the CPU can't operate fast enough

Guess I have to read up on things again.
 
Upvote 0 Downvote
You must log in or register to reply here.

TRENDING THREADS

Latest posts

Moderators online

Share this page

COMPANY
RESOURCES
FOLLOW
Top Bottom