William Yu wrote: > > Well, that would give you the most benefit, but the memory bandwidth is > > still greater than on a Xeon. There's really no issue with 64 bit if > > you're using open source software; it all compiles for 64 bits and > > you're good to go. http://stats.distributed.net runs on a dual opteron > > box running FreeBSD and I've had no issues. > > You can get 64-bit Xeons also but it takes hit in the I/O department due > to the lack of a hardware I/O MMU which limits DMA transfers to > addresses below 4GB. This has a two-fold impact: > > 1) transfering data to >4GB require first a transfer to <4GB and then a > copy to the final destination. > > 2) You must allocate real memory 2X the address space of the devices to > act as bounce buffers. This is especially problematic for workstations > because if you put a 512MB Nvidia card in your computer for graphics > work -- you've just lost 1GB of memory. (I dunno how much the typical > SCSI/NIC/etc take up.)
I thought Intel was copying AMD's 64-bit API. Is Intel's implementation as poor as you description? Does Intel have any better 64-bit offering other than the Itanium/Itanic? -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073 ---------------------------(end of broadcast)--------------------------- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
