<b>Updated</b> CPU Cheatsheet - Seven Years of Covert CPU Operations

74 Comments

View All Comments

• JarredWalton - Friday, August 27, 2004 - link

  Regarding pipeline lengths on Intel products, there are numerous sources that state the P6 core was a 12 stage design. Perhaps the Interger pipeline was shorter and the FP was longer? I don't know for sure, but the majority of information I have read says P6 (PPro, P2, P3, Cel, Cel-2) were all the same core and were all 12 stages. Here's a link to one of the more authoritative CPU information guys that I have read, Jon "Hannibal" Stokes:
  
  http://arstechnica.com/cpu/004/pentium-1/pentium-1...
  http://arstechnica.com/cpu/004/pentium-2/pentium-2...
  
  Those contain a histort of the Pentium architecture. Unless you can provide a more definitive source for pipeline lengths, I tend to believe Hannibal. I also heard at the time the original P4 launched that it had "as few as 20 and as many as 28 stages, depending on the instruction being executed and other factors." Something like that. Most people stuck with the "20 stage" figure, but it has become increasingly clear that it was not a straight 20-stage design.

• IntelUser2000 - Friday, August 27, 2004 - link

  Another correction: the article states 12-stage pipeline for P6 cores? No, its 10, I don't know why some people say P6 cores and its related processors have 12 stage pipelines(exception being PM, because they ARE a different architecture, just not radical as P4), when its 10!!!

• IntelUser2000 - Friday, August 27, 2004 - link

  First, some corrections.
  
  mostlyprudent, P4 Willamette is only available up to 2000. They are actually available from 1300-2000. Over 2000 is Northwood cores, which have 512KB L2 cache and is 0.13 micron process.
  
  Second, why don't anybody seem to notice the pipeline numbers for Prescott on Page 6?
  
  "The Prescott further extended the NetBurst pipeline to 23 stages in addition to the 8 fetch/decode stages. For whatever reason, Intel generally describes the pipeline of the Prescott as 31 stages while only calling the earlier design a 20 stage pipeline."
  
  What the hell? Is it actually true? Can the writer, Jarred Walton, please answer this question? Did you just get the facts wrong or is it true that Prescott does have 23 stage pipelines?

• FlameDeer - Tuesday, August 24, 2004 - link

  Thanks Jarred, very good article! Very useful and helpful processor performance comparison, much better than Intel "BMW" naming! :)
  
  Some small correction at page 3 Intel Cheat Sheet table:
  Entry no.3 Mendocino is 250nm, 154mm2 only
  Entry no.7 Deschutes Bus Speed is 66 MHz

• JarredWalton - Tuesday, August 24, 2004 - link

  #36 - I suppose I should have been consistent with the bus speeds. Intel's really is quad-pumped and AMD's really is double pumped. Somehow along the way I redid the Intel side to have the quad pumped bus speed and I didn't redo the AMD side. The Netburst architecture likely benefits a little more from the increased bus speed, but if AMD certainly benefits as well. I'll include that in my updated version later this week. (My left wrist needs a rest. I don't want to risk carpal tunnel syndrome.)
  
  On the HyperTransport side of things, I really don't regard the HT bus speed as being that important. The old style bus (Athlon Socket A) was a 64-bit 400 MHz bus (200 MHz double-pumped - at least on the 3200+) while HyperTransport is a 16-bit 800 MHz bus. I think that's right, anyway. So 16-bit * 800 MHz (bidirectional) is the same as 400 MHz * 400 MHz (unidirectional). Bleh. Whatever the case, I'm pretty sure the HT bus doesn't really make for the A64 being faster. It helps out tremendously in the Opteron with multiple processors, but that's different.

• johnsonx - Tuesday, August 24, 2004 - link

  to #38
  
  There are two Thoroughbred B AXP 2600's. 133/266FSB @ 2133 Mhz (multiplier 15), and 166/333FSB at 2083Mhz (multiplier 12.5). Yours sounds like a 166/333FSB model.
  
  

• mrmorris - Tuesday, August 24, 2004 - link

  #15
  My 2600+ AMD XP runs 2083MHz and its Thoroughbred-B!

• magratton - Monday, August 23, 2004 - link

  #34 - Sweet. The article made me remember all those years, and that post gave me a great chuckle. Peace! Being an avid comments reader (though not so much a contributor) it is good to finally put a name to a.. well.. a name. Peace!

• mlittl3 - Monday, August 23, 2004 - link

  Jarred
  
  Don't mean to be persistent but I was wondering what your thoughts about the bus speed listings were.
  
  Should AMD Athlon processors be listed with bus speeds like 100, 133, 166, 200 MHz or should it be 200, 266, 333, 400 MHz? Likewise for the AMD Athlon 64, FX, Opteron. They use hypertransport running anywhere from 600 to 1000 MHz and don't advertise a bus speed since the memory controller is integrated (even though everyone knows its 200 MHz X multiplier).
  
  If the current listed speeds are the way it should be written, what about the Intel bus speeds of 400, 533, 800 and 1066 MHz? These really are 100, 133, 200 and 266 MHz when calculating the actual processor speed.
  
  Do the Intel quad speed bus speeds really reflect the actual bus speed wherease the AMD double bus speed do not?
  
  Just wanted to be clear. Thanks. Can't wait for the GPU cheat sheet.
  
  Mark

• JarredWalton - Monday, August 23, 2004 - link

  Umm... crap, sort of let the cat out of the bag there. If the "JW" at the end of the other name didn't clue you in, it should be blatantly obvious who I am now. (Although only people that read the news and article comments are likely to have seen the name.)