DDR3 compatability question

The Vengeance runs at 1.5v and the XMS3 runs at 1.65v so it may be a problem getting them both to run at 1600 CL9 as rated.

Jim

I assume you are running Windows 7 64bit as 32bit wont see anything over 4GB.

I would go with this one. I think it is the same you have now and you would then have 1 stick in each channel. Three sticks would not be the best solution as AMD CPUs have shown problems with more than 2 sticks of memory especially at speeds above 1333.

Corsair CMZ4GX3M1A1600C9 4GB 1600MHzCL9 DDR3 Vengeance | eBay UK

Jim

If wanting to go with dual-channel, I would buy both modules as a matched kit, as they would then be certified to work correctly together. Even seemingly identical modules (same model/manufacturer) may or may not work correctly together if purchased separately. See DDR2 Memory Issues Affecting System Reliability for a similar thread on the subject.

You're welcome. :)

As regards the question you posted above, at higher memory speeds timing becomes more and more of an issue. If you look closely at your motherboard, you will see that the tracks between the RAM slots and the memory controller, be it the Northbridge or the CPU itself, tend to zigzag a lot. This is to ensure that signals from/to the furthest slot arrive/leave at the same time as the nearest one (in between slots are similarly connected and arranged). Unfortunately, because of the physical constraints of the motherboard, there is a limit to this. In an ideal world, if you were able to straighten out all the data lines between the RAM slots and the controller, you would find that the lengths would be absolutely identical. In practice, you would find that the lengths could vary by upto 2mm or so. It doesn't sound much, but at higher and higher frequencies this variation in length becomes more and more significant. Not to mention the inductive and capacitive crosstalk that can occur at higher frequencies, a feature utilised in many older TV UHF tuner modules where the inductors were simply tracks on the PCB and capacitors (in the coupling sense) were 2 or more such tracks in parallel with each other. To overcome this, many motherboards will limit the maximum speed when more than a specified number of slots are used.

Also the current AMD CPUs have the memory controller in the CPU and is designed to run at 1333. Since you have a newer version of the CPU you may not have a problem. If you do you can try and change your memory to the slower 1333 speed. There are other tweaks that may work also but many people have no problems.

Jim