Personal computing discussed
Moderators: renee, Flying Fox, Thresher
DPete27 wrote:Are you sure you put the RAM in the correct slots? I might be dating myself, but IIRC, AMD is slots 1&2 are paired and slots 3&4 are paired. Check your mobo manual. Since you're running a 4GB and an 8GB stick in paired slots, the mobo defaults to the lowest common denominator for addressing dual channel which is 2x4GB. Add the 4GB in slot 3 and there's your 12GB.
PS. Intel mobos pair slots 1&3 and 2&4
The Swamp wrote:I wonder why the BIOS sees all of the RAM? Very odd.
The Swamp wrote:I'll have to take a look at the manual and see what it says about memory configurations. The board is a Gigabyte F2A85X-UP4.
I've run three sticks before in other boards, but it's been a very long time. It might be that I cannot use only three sticks, that it has to be four. I don't really have a lot of experience with late model AMD boards and chipsets. The RAM is all the same speed, DDR3-1600.
I wonder why the BIOS sees all of the RAM? Very odd.
The Swamp wrote:Okay, looks like the problem is solved. It seems to have been an issue with the placement of the sticks. I put the 4GB sticks in slots 2 and 4 from the CPU. I put the 8GB stick in slot 3. Booted into Windows and now it sees all 16GB.
Thanks for the suggestions, guys. I assume I will need to get another stick if I want dual channel again?
demolition wrote:If you are using an odd number of sticks, it should always drop down to single-channel operation. This also means that you might experience a faster system if you remove the 8GB stick and let it run with 2x4GB in dual-channel. Again, CPU-Z should be able to tell you everything you need to know, including if you are actually running in dual-channel mode.
just brew it! wrote:If you have a different amount of RAM on each channel, then yes at least some of your RAM will necessarily be operating single-channel.
But since he's got 2x4 and 1x8, equal amounts of RAM on each channel is doable, depending on which slots those sticks are in. It is possible (likely?) that this is the situation he's in now.
The Swamp wrote:I've heard that VMs are extremely RAM-intensive, but that's mostly what can use up 16+GB of memory under typical conditions. I'm not entirely sure what VMs are, or what they are used for. Is it for using multiple OSs at once? I may have to hit up Google and see what's what.
just brew it! wrote:but since I normally don't do a lot of stuff natively in OS X, I can allocate a large chunk of the RAM to the VM
DPete27 wrote:If you don't know what you need 24GB for, you don't need it. 16GB is still plenty.
Topinio wrote:DPete27 wrote:If you don't know what you need 24GB for, you don't need it. 16GB is still plenty.
Objection! (To the second sentence, not the first.)
It depends entirely on the machine being one which is used by only 1 user at a time, who isn't doing much multitasking. Where either of those scenarios is in play, 16 GB is enough (in most cases) -- whereas 8 GB not now -- but IME plenty starts at 24 GB now.