Celeron processor is a good and cheaper alternative to Pentium II,
Pentium III and Pentium 4 microprocessors when the top performance
is not required, and microprocessor and desktop price is important.
The Celeron processors are based on the same core as more expensive
Pentium-branded processors, but usually lack in some features such as
L2 cache size and bus speed. Since the Celeron processor family spans
three generations of x86 microprocessors, the differences between
Celeron and Pentium processors vary depending on the generation.
Please see the tables below for exact differences for each processor
generation. In addition to the differences described below, at any
given point of time the fastest Celerons were usually clocked lower
than fastest Pentium-branded processors. For example, Celeron 600 MHz
was introduced in March of 2000 - 5 months after introduction of Pentium
III 600 MHz, and one week after introduction of Pentium III 866 MHz.
In many cases Celeron processors could be used in the same
motherboards as Pentium-branded processors. Notes in the table below
indicate when Celeron processors require different motherboards.
| Difference between Celeron and Pentium II |
|---|
| Feature | Celeron | Pentium II |
| Package | SEPP
370-pin PPGA | SECC
SECC2 |
| Socket/slot type | Slot 1
Socket 370 | Slot 1 |
| Bus speed (MHz) | 66 | 66
100 |
| L2 cache size (KB) | 0 KB
128 KB on-die cache running at CPU frequency | 512 KB backside cache running at 1/2 CPU frequency |
| Multiprocessing | Officially not supported | Supported |
| Notes | Socket 370 Celeron processors require socket 370 motherboard, but can be used in Slot 1 motherboards with the help of slotket (slocket) adapters. |
| Difference between Celeron Coppermine and Pentium III Katmai/Coppermine |
|---|
| Feature | Celeron (Coppermine) | Pentium III (Katmai) / (Coppermine) |
| Bus speed (MHz) | 66
100 | 100
133 |
| L2 cache size (KB) | 128 KB on-die cache running at CPU frequency | 256 KB on-die cache running at CPU frequency
512 KB backside cache running at 1/2 CPU frequency |
| Multiprocessing | Not supported | Supported |
| Notes | Celeron processors can be used in Slot 1 motherboards with the help of slotket (slocket) adapters. |
| Difference between Celeron Tualatin and Pentium III Tualatin |
|---|
| Feature | Celeron (Tualatin) | Pentium III (Tualatin) |
| Bus speed (MHz) | 100 | 133 |
| L2 cache size (KB) | 256 | 256 KB
512 KB |
| Multiprocessing | Not supported | Supported by some processors |
| Difference between Celeron Northwood and Pentium 4 Northwood |
|---|
| Feature | Celeron (Northwood) | Pentium 4 (Northwood) |
| Bus speed (MHz) | 400 | 400
533
800 |
| L2 cache size (KB) | 128 | 512 |
| Hyperthreading | Not supported | Supported by some processors |
| Difference between Celeron D Prescott and Pentium 4 Prescott |
|---|
| Feature | Celeron D Prescott | Pentium 4 Prescott |
| Bus speed (MHz) | 533 | 533
800 |
| L2 cache size (KB) | 256 | 1024
2056 |
| Hyperthreading | Not supported | Supported by almost all processors |
| Enhanced SpeedStep Technology | Not supported | Supported by some processors |
| Virtualization technology | Not supported | Supported by some processors |
| Difference between Celeron D Cedar Mill and Pentium 4 Cedar Mill |
|---|
| Feature | Celeron D Cedar Mill | Pentium 4 Cedar Mill |
| Bus speed (MHz) | 533 | 800 |
| L2 cache size (KB) | 512 | 2048 |
| Hyperthreading | Not supported | Supported |
| Enhanced SpeedStep Technology | Not supported | Supported |
|
You are correct in saying that the server version of the Pentium III Tualatin was distinguished by the "S" (usually "PIII-S" although the "S" can crop-up elsewhere in the description), and that there was never a "D" designation.
However, the desktop PIII Tualatin running at 1.133ghz (rather than the other 1.2ghz model) did have an "A" designation (usually seen "PIII 1133A"). This was to to distinguish it from the PIII 1133 on the Coppermine core.
Confusing, isn't it. Link:
http://www.cpuscorecard.com/cpuprices/ip3.htm
It should also be noted that the desktop PIII Tualatins also differed from the server PIII Tualatins in that the server models would not run properly in the standard socket 370 Tualatin motherboards.
although they would work, because the server CPUs required different load line characteristics, they would degrade fast.
Link - look at the text starting just above the first chart:
http://www.digit-life.com/articles/tualatinsmp/index.html
about PIII-D
> "PIII or PIII-D Pentium III desktop"?
Yes, P!!!-D isn't official name for this family of CPU...
> The main difference between the Celeron tualatin
> the Pentium III Tualatin and Pentium III Server
> Tualatin
and in cache size... So P!!!-S is some type analogue of Xeon. But one can use this CPU in desktop MoBo, in opposite to [P!!!] Xeon (which can be installed only in Slot2 MoBos)
Some Information to fix
Note: there is two pentium III tualatin types:
PIII or PIII-D ("Pentium III desktop")
133Mhz FSB, 256KB cache, cannot work in dual :(
PIII-S ("Pentium III server")
133Mhz FSB, 512KB cache, dual-capable
If we talk about tualatin there were three types available (including mobile versions) but as we are talking about desktop version there are only two. Why did you wrote "PIII or PIII-D Pentium III desktop"? Intel never called ANY PIII "PIII-D" they just called the desktop version Pentium III and the server version Pentium III-S. There was the desktop version which was only called Pentium III which had 256kb cache. And the Pentium III-S which had 512kb. The main difference between the Celeron tualatin the Pentium III Tualatin and Pentium III Server Tualatin was that the Pentium III Server Tualatin was the only processor capable of running in dual-processing.
Multiprocessing
Celeron Covington/Mendocino is only Celeron, which CAN work in dual mode... however Intel says that this is impossible.
Also Celeron Tualatin has 256KB cache, not 128KB... So there is only two differences between them and "full" Pentium Tualatin:
1) cache latency (celeron's cache is slower by 1 clock cycle)
2) FSB (100 vs 133)
Note: there is two pentium III tualatin types:
PIII or PIII-D ("Pentium III desktop")
133Mhz FSB, 256KB cache, cannot work in dual :(
PIII-S ("Pentium III server")
133Mhz FSB, 512KB cache, dual-capable
UPDATE: Partially corrected the page