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

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