Registered Ram Question

[ZombieJesus]

I have been looking for 2 Dimms of 1 Gig DDR 400 Registered for use in a dual opteron system. Both OCZ and corsair offer matched pairs their latency is rated for 3-3-3-10.

Has any one got ram like this to run at DDR 400 with timings like 2-2-2-10?

 

[LED]

You'll be looking for ever as the RAM needs the extra tick for security reasons and the Opteron has the Memory Controller on the Square not the MoBo

 

[Zepper]

Registered RAM does not work like regular ram as it delays (buffers) writes until the exact edges of the timing pulses. It does this so that more modules can work together timing wise (note that there are usually many more RAM sockets on most dualie/server mobos than normal mobos) - so it is always going to be slower than normal RAM. Just get the shortest CAS time you can afford and be happy. Of course you will want the modules to be both registered and ECC. The idea is reliability rather than speed.

.bh.

 

[Peter]

Registered RAM has extra chips that register the access address, isolating the RAM chips from the common bus to allow more RAM chips total. This is why you have an extra cycle on RAS and CAS latencies above what the actual RAM chips require.

 

[ZombieJesus]

Ah now I am beginning to see. Because of the extra ram chips the latency is worse then say on a 512 dimm.... there are registered ecc 512 dimms sold by both corsair and ocz that reach ddr 400 2-3-2-8 so i still must wonder if you add a weee bit more voltage a 1024 dimm might do 2-3-2-10?