Replies to post #15637 on Advanced Micro Devices Inc (AMD)

[sgolds]

Hi, YB. Some socket 939 answers:

1. Q204, I think.

2. Yes, unregistered DDR.

3. Yes, dual channel.

4. Not known about SMP; probably not.

5. The socket will address local DRAM with exactly twice the throughput of socket 734. Other things affect processor performance so your 10-15% applies to the processor, not the socket.

6. It will be faster for 2-DIMM (4-bank) solutions; registered DDR does not degrade when you add DIMMs so if the user puts in more than 2 DIMMs then DRAM performance will be below socket 940. Most users will use 2 DIMMS and get a speed boost.

Edit: Not sure if the 2 DIMM limit would apply here, it may be doubled to 4 DIMMs - two per memory controller.

7. Cache: 256K? Doubt it. The socket really has nothing to do with cache (except very indirectly in terms of performance tradeoffs). Currently A64 has just over 1MB of cache, I don't know why they would reduce it.

Hope that helps!

[jhalada]

yb,

1. socket 939 comes in Q104?
That is the expectation. AMD will update the official roadmap on November 6.

2. s. 939 will use unregistered DDR, unlike sock 940?
Yes

3. it will be dual-channel?
Yes

4. it will not support SMP?
I am not sure about that. Most likely, it will not support SMP, unless AMD wants to at some point abandon Socket 940 and move entirely to Socket 939, which I don't see as likely.

5. because of #3 sock 939 will be much faster (10-15%) than sock 734 on same frequency?
On apps that like a lot of bandwidth

6. because of #2 it will be much faster than sock 940 on same frequency?
On apps that like low latency (high percentage of apps). Sum of 5 + 6 = Socket 939 will never be slower than either Socket 754 or Socket 940 CPU.

7. 256K cache will come together with sock 939?
Those issues are independent of each other. I would expect 256K chips mostly on Socket 754

8. 256K cache sock 939 is approximately as fast as 1M cache sock 734?
Too many variables to give a reasonable answer.

Joe