If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
Pretty good explanation of x86-64 by HP
I found this whitepaper from HP to be pretty good, it is surprisingly
candid, considering HP was the coinventor of the Itanium. It does a pretty good job of explaining and summarizing the similarities and differences between AMD64 and EM64T, and their comparison to the Itanium's IA64 instruction set. AMD64 and EM64T are "broadly compatible", but IA64 is a different animal altogether. Yousuf Khan http://h200001.www2.hp.com/bc/docs/s.../c00238028.pdf |
#2
|
|||
|
|||
Yousuf Khan wrote:
I found this whitepaper from HP to be pretty good, it is surprisingly candid, considering HP was the coinventor of the Itanium. It does a pretty good job of explaining and summarizing the similarities and differences between AMD64 and EM64T, and their comparison to the Itanium's IA64 instruction set. AMD64 and EM64T are "broadly compatible", but IA64 is a different animal altogether. Yousuf Khan http://h200001.www2.hp.com/bc/docs/s.../c00238028.pdf When did the non-Xeon Prescott P4s start offering EMT64 as listed in the paper? News to me. Does HP know something the rest of the world doesn't? Bill |
#3
|
|||
|
|||
On Sun, 05 Dec 2004 01:02:11 -0500, Yousuf Khan wrote:
I found this whitepaper from HP to be pretty good, it is surprisingly candid, considering HP was the coinventor of the Itanium. It does a pretty good job of explaining and summarizing the similarities and differences between AMD64 and EM64T, and their comparison to the Itanium's IA64 instruction set. AMD64 and EM64T are "broadly compatible", but IA64 is a different animal altogether. Yousuf Khan http://h200001.www2.hp.com/bc/docs/s.../c00238028.pdf Hmm and the following quote: "However, the latency difference between local and remote accesses is actually very small because the memory controller is integrated into and operates at the core speed of the processor, and because of the fast interconnect between processors." is relevant to another discussion here. I wish we could get a firm answer on this one. Rgds, George Macdonald "Just because they're paranoid doesn't mean you're not psychotic" - Who, me?? |
#4
|
|||
|
|||
George Macdonald wrote:
On Sun, 05 Dec 2004 01:02:11 -0500, Yousuf Khan wrote: I found this whitepaper from HP to be pretty good, it is surprisingly candid, considering HP was the coinventor of the Itanium. It does a pretty good job of explaining and summarizing the similarities and differences between AMD64 and EM64T, and their comparison to the Itanium's IA64 instruction set. AMD64 and EM64T are "broadly compatible", but IA64 is a different animal altogether. Yousuf Khan http://h200001.www2.hp.com/bc/docs/s.../c00238028.pdf Hmm and the following quote: "However, the latency difference between local and remote accesses is actually very small because the memory controller is integrated into and operates at the core speed of the processor, and because of the fast interconnect between processors." is relevant to another discussion here. I wish we could get a firm answer on this one. Not sure if this is exactly what you are looking for in the way of a "firm answer", but the latencies in a Opteron system a 0 hops 80 ns uniprocessor (Local access) 100 ns multiprocessor (Local access, with cache snooping on other processors) 1 hop 115 ns 2 hops 150 ns 3 hops 190 ns I couldn't find my original source for those numbers, and the two and three hop numbers above are a little higher than I remembered them as being. This time around I got them from this thread: http://www.aceshardware.com/forum?read=80030960 That thread refers to this article: http://www.digit-life.com/articles2/amd-hammer-family/ which gives slightly different numbers for a 2 GHz Opteron with DDR333: Uni-processor system: 45 ns Dual-processor system: 0-hop - 69 ns, 1-hop - 117 ns. Four-processor system: 0-hop - 100 ns, 1-hop - 118 ns, 2-hop - 136 ns. I don't know if any of the numbers above are for cache misses or if they are averages that include both hits and misses. |
#5
|
|||
|
|||
"Bill Bradley" wrote in message nk.net... Yousuf Khan wrote: I found this whitepaper from HP to be pretty good, it is surprisingly candid, considering HP was the coinventor of the Itanium. It does a pretty good job of explaining and summarizing the similarities and differences between AMD64 and EM64T, and their comparison to the Itanium's IA64 instruction set. AMD64 and EM64T are "broadly compatible", but IA64 is a different animal altogether. Yousuf Khan http://h200001.www2.hp.com/bc/docs/s.../c00238028.pdf When did the non-Xeon Prescott P4s start offering EMT64 as listed in the paper? News to me. Does HP know something the rest of the world doesn't? Bill www.overclockers.co.uk had some a few weeks back, and htey sold very quikly. I think theres a few more in now. hamman |
#6
|
|||
|
|||
On Sun, 05 Dec 2004 06:44:31 GMT, Bill Bradley
wrote: Yousuf Khan wrote: I found this whitepaper from HP to be pretty good, it is surprisingly candid, considering HP was the coinventor of the Itanium. It does a pretty good job of explaining and summarizing the similarities and differences between AMD64 and EM64T, and their comparison to the Itanium's IA64 instruction set. AMD64 and EM64T are "broadly compatible", but IA64 is a different animal altogether. Yousuf Khan http://h200001.www2.hp.com/bc/docs/s.../c00238028.pdf When did the non-Xeon Prescott P4s start offering EMT64 as listed in the paper? News to me. Does HP know something the rest of the world doesn't? Not that they know something the rest of the world doesn't, just that they have access to processors that most of us do not. IBM sells them as well, but for the time being Intel will ONLY sell them for use in servers. Why? I really don't know. Maybe it's just a bit too much crow for them to eat after saying (only a bit over a year ago) that 64-bit wouldn't be useful for the desktop until the end of the year? ------------- Tony Hill hilla underscore 20 at yahoo dot ca |
#7
|
|||
|
|||
Tony Hill writes:
Not that they know something the rest of the world doesn't, just that they have access to processors that most of us do not. IBM sells them as well, but for the time being Intel will ONLY sell them for use in servers. Why? I really don't know. Maybe it's just a bit too much crow for them to eat after saying (only a bit over a year ago) that 64-bit wouldn't be useful for the desktop until the end of the year? How much does Intel stockpile? Could it be that they have warehouses full of already produced non-64-bit processors, and those want to be sold at the projected prices, not thrown away? best regards Patrick |
#8
|
|||
|
|||
Bill Bradley wrote:
When did the non-Xeon Prescott P4s start offering EMT64 as listed in the paper? News to me. Does HP know something the rest of the world doesn't? It must have been at least two or three months now, I posted a message about it in one of these newsgroups. Google Search: g:thl403337196d http://groups.google.ca/groups?q=g:t...e .rogers.com or, http://tinyurl.com/6tnjy Yousuf Khan |
#9
|
|||
|
|||
George Macdonald wrote:
Hmm and the following quote: "However, the latency difference between local and remote accesses is actually very small because the memory controller is integrated into and operates at the core speed of the processor, and because of the fast interconnect between processors." is relevant to another discussion here. I wish we could get a firm answer on this one. Yeah, but that's why I think AMD insists on calling their multiprocessor connection scheme as SUMO (Sufficiently Uniform Memory Organization), rather than NUMA. It's not worth headaching over such small differences in latency, is basically what they're saying. Yousuf Khan |
#10
|
|||
|
|||
Patrick Schaaf wrote:
How much does Intel stockpile? Well, according to the Reg, http://www.theregister.co.uk/2004/12/03/intel_eol_p2/ they just finally announced EOL for the Pentium-II. "The Register reveals that you'll be able to continue ordering the part for a year, with the last trays leaving the chip giant's Pentium II warehouse on 1 June 2006." Could it be that they have warehouses full of already produced non-64-bit processors, and those want to be sold at the projected prices, not thrown away? Whether there is any connection between your hypothesis and the Reg news, is left as an exercise for the reader :-) -- Regards, Bob Niland http://www.access-one.com/rjn email4rjn AT yahoo DOT com NOT speaking for any employer, client or Internet Service Provider. |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
· · · Have You Heard The Good News? · · · | [email protected] | General | 0 | January 29th 05 07:59 PM |
(",) Good News for Google Groups, Usenet and Other Users | [email protected] | General | 0 | January 29th 05 06:30 AM |
(",) Good News for Google Groups, Usenet and Other Users | [email protected] | General | 0 | January 29th 05 03:14 AM |
(",) Good News for Google Groups, Usenet and Other Users | [email protected] | General | 0 | January 28th 05 04:13 PM |
Anyone know a good deal on a good mp3 player? | travel | General | 1 | November 30th 04 10:51 PM |