If you expect heavy cgi use then go for the PIII and the scsi drive. If you just expect moderate cgi use and serving html pages than the celeron will be more than enough.
The RAM is the key here. The celeron system with the extra ram will most definitely outperfrom the PIII once you get a few dozen sites on it. If your swap space on the scsi drive is large, than it doesn't matter what kind of cpu you have. But, like mentioned above, you can always add ram.
Even though the PIII has a faster cpu, I personally recommend going with the celeron... because your sites will chew through the 128 ram in a few seconds... the CPU will be far enough unles they are all running huge CGIs.
RAM will be more used, especially if you have stuff like ASP, mod_php, MySQL or mod_perl.
raw benchmarks do not equal superior performance in real world applications. You can have a 1ghz cpu with 128 megs of ram, plop 200 moderately busy sites on it and a celeron 366 with 512mb of ram will outperform it. The key here is to have as much ram as possible to avoid large swap files and minimize disk i/o activity.
Now, put the same amount of ram in the P3 and that's a whole different story.
2. swap space is virtual ram. A portion of hard drive space is allocated for use as ram. It can be run on a non-scsi drive, but scsi is faster than ide, therefore providing better performance.
3. Disk Input/Output is measured with certain programs. But an easier way to measure I/O load is to listen to the hard drive. If it's continually making noise, e.g. always reading and writing data, then it's under heavy load. The common term for that amount of load is thrashing.
1. 256k of cache refers to the memory that is built into the cpu. It is not an actual chip since it's on the die of the cpu. It's much faster than having to access the RAM because it runs at the clock speed of the cpu (hence 650 mhz = cache that runs at 650 mhz).
2. Swap space, as JTY has mentioned, is your virtual memory. Virtual memory is space on your harddrive that imitates RAM (when you run out of physical RAM your OS emulates it buy using the hard drive). But accessing the hard drive is much, much slower than accessing data from RAM.
3. The more RAM you have in your computer the less your computer will have to resort to using "Virtual Memory" or "Swap" space on your hard drive, therefore minimizing hard drive input/output (which is very slow in comparison to RAM or Cache access)
Originally posted by tabernack 256k of cache refers to the memory that is built into the cpu. It is not an actual chip since it's on the die of the cpu. It's much faster than having to access the RAM because it runs at the clock speed of the cpu (hence 650 mhz = cache that runs at 650 mhz).
Thanks Tabernack !!!
I think I still have a little doubt about one little thing. You mentioned that the cache runs at the clock speed of the CPU. I am slightly confused here.
I am asking to clarify this because I think that RAM is extremely fast ie. data is transferred in nanoseconds... billionths of a second. Wouldn't a cache running at the clock speed of the CPU be much slower than accessing RAM then?
RAM access, even though it seems to be very fast (nanoseconds), is still much slower than accessing the cpu cache. Don't forget, when the cpu has to make a request to retrieve data from RAM it has a much further distance (and at a much slower speed (ie: pc100 = 100mhz RAM) then if the cpu retrieves data from it's own cache.
let's say you want a glass of water right NOW, and you have 2 choices:
1) A glass of water right in front of you sitting on your desk.
2) A glass of water that you must get by going to the fridge, pouring some into a glass, and then returning to your desk.
Which one will take less time?
That's why Xeon processors are so expensive, because on-die cache is very expensive and Xeon's have lots of it.
I just want to clarify that PII's and first generation PIII's had cache that ran at half the cpu clock speed (just wanted to mention that so someone wouldn't have to post it)