Hypertransport - Less than 1000

[Melchior]

When overclocking and forcing to run the LDT @ 3x or something, that results in less than 1000 HT ( from a normal 5x200), how does this affect any part of the system's performance?

Or to sum up, how does the HT affect system perforamnce?

 

[Concillian]

Very little.

Consider that the primary use of the HT in a single processor board is to provide a path for communication between the chipset and the CPU. Consider also that traditionally the memory information would travel through this path, but in the A64, memory bus is seperate (direct from mamory to memory controller on CPU). This reduces the need for bandwidth between the processor and CPU.

At the same time, an 800 MHz HT is capable of 3.2GB/sec (in each direction, marketeers will call this 6.4GB/sec)
1000 is 4.0 GB/sec (in each direction, again marketed as 8 GB/sec)

Compare that with the FSB of Intel (communication between the CPU and chipset), which is 800 MHz and capable of 6.4GB/sec and it has to carry the memory data too

Because of the A64 design, with memory on a seperate link, HT is not terribly important in overall system performance.

 

[otispunkmeyer]

yeah with it not carrying memory data, the HT is very rarely saturated.....ive seen HT of just 200 perform no worse than a HT of 800

 

[CaBoOse999]

Yeah don't worry too much about that.

 

[Melchior]

Very cool, thanks guys. My HT is @ 810 x 2 = 1600 right now. Which should be fine I guess