Advanced Micro Devices Inc (AMD)

[upc]

More evidence that Intel iAMD64 performance sucks:

http://www.aceshardware.com/forum?read=115092693


Can you summarize?
By Trinity on Sunday, August 1, 2004 5:19 PM EDT
I had posted here a link to an interview with a Senior VP of Windows development who pretty much said that Intel's implementation wasn't up to the mark compared to AMD's. I'm sorry but I can't seem to find that link. If others can then please post here. Also there have been many discussions on RWT about the Linux folks talking about issues with Intel's implementation. Search for "bounce buffers" in relation to AMD64 and EMT64. I'm not totally aware of the details but it has something to do with 64 bit DMA's in IO devices like PCI cards etc and them being able to access a 64 bit address space or something like that. If anyone else knows the details or links, kindly post them here.

Edit: I found a link about the issues the Linux folks talked about -
http://lwn.net/Articles/91870/
"On some architectures - notably AMD's x86_64 - an I/O memory management unit (IOMMU) is provided. This unit remaps addresses between the peripheral bus and main memory; it can make any region of physical memory appear to exist in an area accessible by the device. Systems equipped with an IOMMU thus have no problems allocating DMA memory - any memory will do. Unfortunately, when Intel created its variant of the x86_64 architecture, it decided to leave the IOMMU out. So devices running on "Intel inside" systems work directly with physical memory addresses, and, as a result, the more limited devices out there cannot access all of physical memory. And, as we have seen, the kernel has trouble allocating memory which meets their special needs."

Edit 2: Okay I found the other link from Winsupersite also which make it difficult to find archived articles easily -
http://www.winsupersite.com/showcase/muglia_winserver.asp

"Paul: Are you seeing any difference between AMD's [64-bit] stuff and Intel's stuff?
BM: Yes. [Smiles]

Paul: Would you care to clarify that? [Laughs]
BM: Well, AMD has done a good job ...

[Laughter]

Paul: OK, I realize these companies are both important partners...
BM: I think both have invested very heavily... and I'm sure that customers will be happy with either solution.

Paul: All righty.

[Laughter]

BM: Are there differences? Yes, there are differences.
Paul: OK, so how do these companies differentiate their 64-bit products?

BM: So there are some things that AMD's done that Intel hasn't done, and I'm sure Intel will continue to invest here, and will do a really good job. AMD led the way on this one. There's no doubt they led the way on this one."