On Tue, Dec 11, 2001 at 05:05:24PM -0700, Gary Hennigan wrote: | dman <[EMAIL PROTECTED]> writes: | > On Tue, Dec 11, 2001 at 01:17:30PM -0500, David Teague wrote: | > | | > | | > | If you put more RAM in a computer system than the caching system | > | will suppport, the system will run more slowly than it would with | > | less RAM. IF I understand correctly, the amount of RAM depends on | > | the amount of tag RAM. | > | | > | I have 512 MB on my Abit MoBo with a 1GHz Athlon. | > | | > | How do I determine how much RAM the L1 cache in a 1GHz Athlon will | > | support? | > | > According to | > http://www.amd.com/us-en/Processors/ProductInformation/ | > 0,,30_118_756_759%5E1151,00.html | > | > (all on one line) | > | > Cache Architecture: The AMD Athlon processor boasts a 384K total | > full-speed on-chip system cache including 128K L1 cache--four | > times that of Intel's Pentium III processor--and 256K on-chip | > full-speed L2 cache. | > | > | > There is no limit on the amount of system RAM based on processor | > cache. Certainly when you have many cache misses, you lose | > performance, but the whole purpose of cache is to try and guess which | > memory you will need next (through some hueristic algorithms) so that | > you have a cache hit and don't have to go all the way out to that very | > (relatively!) slow memory. | | Umm, not quite. There can be a limit on the amount of RAM that can be | cached based on the processor, but more common is a limit based on the
| http://www.makeitsimple.com/articles/ramguide/ramguidep6.htm#Cache_RAM_Issues (added the anchor reference) Oh, I had never heard of a limit as to _which_ portion of main memory was capable of being cached before. I thought he was asking if all 512MB could be cached (simultaneously). (Hence my response of, "no, only 384KB can be cached at any given time") -D -- A)bort, R)etry, D)o it right this time
