P4 better than Celeron when encoding

[mate]

Does a P4 give better performance than a Celeron at the same frequency when doing MPEG-1/2 encoding? Back in my ray tracing days I learned that the size of CPU (L1/L2) cache had almost no impact on the 3D rendering performance, since there was so much data involved. I suppose there is far, far more data involved when encoding MPEGs.

Is there any difference between the P4 and the Celeron other than the CPU cache size?
Is the FSB faster? Would that impact encoding speed?

[pixel]

From what I've seen the P4 and Celeron's do not actually have much different times for encoding because it is only one task they are running so pure GHz matters, so equal speed will be almost the same.

The Celeron only goes up to 2.7GHz and only has an FSB of 100MHz (runs at 400MHZ)

The P4 goes up to 3.2GHz and they can come in FSB of 100MHZ (400MHz), 133MHz (533MHz) and 200MHz (800MHz). THe 800MHz FSB models have hyper-threading, which makes the system think it is running two processors, which boosts the encoding speeds.

If you had an 800MHz P4 to compare against a celeron, the 800MHz P4 would win out easily. If you are really thinking about getting a Celeron, I, and most other people will suggest against it. You could easily buy a good performance Athlon XP for almost the same as a Celeron. An athlon XP will also let you do more tasks at once because of its larger cache size, whereas with the Celeron you could probably only do one task. (I have actually used a 2GHz socket 478 Celeron system and it was impossible to burn a CD and surf the internet at the same time-no joke).

[mate]

...pure GHz matters...

That is why I was considering a Celeron. For the price of a 2.7 GHz Celeron I would only get a 1.9 GHz Athlon. Or is the AMD marking ("2600+") comparable when it comes to encoding???

[pixel]

As an Intel user I have no idea how the AMD Athlon XP will compare in terms of encoding, but the 2600+ means it is comparable to a 2.6GHz P4 in normal use I believe.

If you are building a seperate system puely for video editing/encoding and nothing else, a Celeron should be fine. If you are building yourself a brand new PC for normal use, and you are not willing to pay for a P4c, I would suggest you get an Athlon XP, even if it may be a slighty slower speed than the Celeron, because the faster FSB and higher L2 cache will make it run better.

Just a rough summary to help you decide what you need:

Basically, Intel Celerons and AMD Durons are really only good for doing one task at a time, in which GHz usually matters.

If you plan on doing many applications at once, FSB speed and L2 cache come into play, so AMD Athlons and Intel P4s are the best for this usage.

[sterno]

Most of the benchmarks I've seen show the Celeron as being slower than a Pentium 4 at the same clock or an Athlon at the same performance rating for most types of media encoding. The Celeron architecture is similar to that of the P4, but it's often crippled by the undersized cache.

[Ripper2860]

Audio / Video encoding does not benefit from L2 cache size, as the cached data is not re-used and therefore must be fetched from RAM anyway. The real factors in encoding are PROCESSOR SPEED and FSB SPEED. A P4 Celeron with an O/C'ed FSB to match a full-blown P4 at the same CPU SPEED and FSB SPEED will perform virtually identically. L2 cache size matters in many applications, but audio and video encoding are not one of them.

Now as for AMD vs. Intel. The rule of thumb is that due to the increased stages and deeper pipelines. a P4 or P4 Celeron will execute approx .75 (3/4) of an instruction per cycle where as AMD will execute 1.0 instruction per cycle. IPC is the real criteria for measuring dissimilar CPU architectures. Intel needed larger caches to make up for the lower IPC, and the larger cache helped tremendously (i.e. Northwood vs Williamette) -- in applications that benefit from L2 cache. However, audio/video encoding, again, does not benefit here.

**** Note -- Intel CPU's suporting HyperThreading are a completely different story, and add considerable advantage over Celeron's which do not. ****

Another factor to weigh in, if the PC is to be used exclusively for audio/video encoding, is whether the selected encoding application supports or is optimized for SSE-2, such as TMPGenc. This can provide a pretty significant performance increase over running the application on a non-SSE2 compatible chip (i.e. Athlon XP family). Both the P4 and Celeron P4 support SSE2.

**** Additional note -- Athlon 64's, Opteron's, etc., are a completely different story as they have a different architecture and do support SSE-2 ****

For audio/video encoding a Celeron is as good as a full-blown P4 (assuming =GHz, =FSB, and no HT). Now when comparing Intel processors to AMD processors, the factors are SPEED (calculated as IPC x MHz) and SSE2 support (if the encoder application uses it). Not L2 cache size.

For Audio/Video encoding use, the P4 Celeron represents an excellent value and potentially substantial savings when compared to full-blown P4, with virtually no performance hits. You could put the savings towards a H/W Mpeg2 encoder card!

[sterno]

A general comparison of Athlon and Celeron (no new P4s, it's a "budget" CPU comparison):
http://www.anandtech.com/cpu/showdoc.html?i=1927
No MPEG-1/2 encoding, but they do a DivX encode.

A comparison of lots of CPUs, including Athlon and P4:
http://www.tomshardware.com/cpu/20030217/index.html
This one includes tests of MP3 and MPEG-2 encoding.