How do i determain the size of my memory

I found an anomaly in SPECCY yesterday. I was given a Dell Inspiron 6000 Notebook running WinXP with 1GB RAM [2x512MB]. I ran SPECCY and it showed a maximum of 4GB possible but Crucial said 2GB maximum. Having some compatible modules I gave 4GB [2x2GB] a try but some would show only 2GB, one pair would flash the screen and immediately shut down while another pair wouldn't boot at all. It's happy with 2GB [2x1GB matched].

In case anyone has forgotten - RAM speed in this case is not an issue. The OP can use faster modules if he/she wants. One can verify what can be put in using the Crucial website, which I have found to be very accurate. Just my 2 cents.

I think i am getting a picture of the memory i would need. Still not sure of the various speeds, but ignatzatsonic told me what speed I need. I ran the Crucial test, just to see what it showed, see screen shot.

The only other question is: Does different memory work with different CPU's? I ran into this while looking at memory:

"...compatible with Dual Channel Intel Core i5 CPU for P55 chipset motherboard, Dual Channel Core i7 CPU for P55 chipset motherboard."

I have an AMD Athlon(tm) II X2 220 Processor. Or is memory stupid and does not care what CPU you have?

The CPU doesn't really care as long as the motherboard supports the modules. I've used the same modules on motherboards for the Intel CPU and the AMD CPU.

A note on the speed: I've always been able to use the faster in slower slots, e.g. PC2-6400 in slots that called for PC2-4200 or PC2-5300. Seems the modules will 'fall back' to slower speeds or run at the same speed as the slowest in use. As Crucial says it's usually best to use the modules in matched pairs.

Some brands aren't compatible with other brands so maybe having all modules from the same vendor is best.

Memory requirements are driven by the motherboard. Likewise, only certain CPUs can be installed on any given motherboard.

If you built your own PC and used an Acme model X motherboard, you'd go to the Acme website and look up up their model X motherboard to see what RAM it required and buy accordingly. Acme probably would have a compatible RAM list, although some RAM not listed would also work if the primary specs matched.

The Crucial configurator is quite accurate, with very few errors.

And what is the result of using sticks with differing voltages, ie; 1.35 or 1.6 instead of the 1.5v nom

You can use only the voltages supported by the motherboard, doing otherwise risks damage to the module or board, or both.

It matters less what you have now, since they are going to be replaced.

Pegatron 2a99 specs say only this, apparently:

2 x 240-pin DDR3 DIMM slots Supports Dual Channel DDR3 1333/1066 MHz non-ECC, un-buffered (Max 4GB)

No reference to voltage.

You can Google trying to find info on recommended voltage, but may not have any luck.

Timings aren't critical. Lower numbers are better, but you'd be hard pressed to tell. If you buy a matched pair, each stick will have the same timings.

If you can't find over-riding evidence to the contrary, I'd trust what the Crucial configurator recommends and I'd probably buy from them. Buy whatever voltages are on their list for your board.

I recall reading about 10600 versus 10660, but I wouldn't get in a lather about it. Stay with a matched pair from Crucial's list unless it outright conflicts with the Pegatron 2a99 specs of:

2 x 240-pin DDR3 DIMM slots Supports Dual Channel DDR3 1333/1066 MHz non-ECC, un-buffered (Max 4GB)

Yes, after researching it i agree, the 10600, 10666, 10700's are basically the same:

"Different manufacturers label their DDR3 1333MHz RAM with different theoretical maximum bandwidth numbers. 10600/10660/10666 all mean the same 1333MHz speed, so it doesn't matter which kind you get."

I will stay with 1.5v.

But the Crucial configurator recommends PC3-12800 memory (which is a DDR3-1600). (post #13)

Why is this when everyone here is recommending PC3-106xxx

I read that:

"PC3-10600 is also known as DDR3-1333 (clocked at 1333MHz)
PC3-12800 is DDR3-1600

Most DDR3-1600 should be capable of falling back to DDR3-1333, often with better timings, as if the memory chips can do CL9 at 1600, they can usually do CL7 at 1333

You will find many sites suggesting RAM that is one step higher speed than is actually used by the system."

So is the PC3-12800 a better stick, i mean faster than the 1333/106xxx

MetalMan228 said:

Yes, after researching it i agree, the 10600, 10666, 10700's are basically the same:

"Different manufacturers label their DDR3 1333MHz RAM with different theoretical maximum bandwidth numbers. 10600/10660/10666 all mean the same 1333MHz speed, so it doesn't matter which kind you get."

I will stay with 1.5v.

But the Crucial configurator recommends PC-12800 memory though. (post #13)

Why is this when everyone here is recommending PC3-106....

The Crucial configurator may be wrong.

The specs quoted earlier in this thread for your alleged Pegatron board could be wrong. Maybe you don't in fact have that motherboard. Maybe you do.

You need to decide for yourself what motherboard you have and then do your best to research it, down to the board revision number level.

If that conflicts with Crucial, I would call Crucial and mention your documentation and ask what gives. I've dealt with their customer support before and had good luck.

I've never heard of anyone not being able to return RAM to them if the configurator is wrong.

They may or may not have a suitable answer. I'd like to tell you to always rely on the manufacturer's web site, but I suppose that could be wrong too.

It of course is possible the board would run fine on either of the choices.