Forum OpenACS Q&A: AMD .vs Intel; GCC et all

Posted by Louis Gabriel on 07/14/01 01:26 AM

Hi,

Anyone have thoughts on the AMD .vs Intel CPUs?

I've been thinking about building a new computer. I've never had a
system with an AMD CPU....yet. I may press the new box into service
as a "home" or personal server.

The factor I've been wondering most about is GCC. I've read that the
compiled code is much better optimized for the Pentium III than the
AMD Athlon; that GCC doesn't really optimize for the AMD chips much at
all. I don't know how much a performance factor compiling from source
with the GCC on the Athlon .vs Pentium would be. Does anyone?

Anyone have input on this issue?

Also, I would enjoy reading any thoughts you care to share on the
various chipset, motherboard and memory options for a Linux developer
or server box. Stability and reliability are what I value
highest...but that's just me.... how about you? :o)

(I love this stuff!)

Thanks,

Louis

2: Response to AMD .vs Intel; GCC et all (response to 1)

Posted by Robert Ezman on 07/14/01 02:24 AM

The first time I read your question I thought that the following link had info on exactly what you were asking. Then I realised the twist. You're not asking about compiler performance but rather compiled code performance.

I figured you might be interested in the story anyway. I got the link from slashdot last night. It's a comparison of multi and single processor AMD and Intel machines. One of the benchmarks is building the Linux kernel. (i.e. performance of GCC)

http://www.gamepc.com/reviews/printreview.asp?review=asmpl&mscssid=&tp=

3: Response to AMD .vs Intel; GCC et all (response to 1)

Posted by Andrew Spencer on 07/14/01 04:17 AM

Actually, in a sense I believe the above link does answer Louis'
question. Is not GCC compiled with GCC? Even if GCC does not compile
100% efficient AMD code, the results at the above URL show that
(running GCC compiling the Linux kernel) an AMD chip outperforms it's
comparable Intel counterpart.

4: Response to AMD .vs Intel; GCC et all (response to 1)

Posted by Edmund Lian on 07/14/01 06:06 AM

Clock-for-clock, an AMD Athlon is generally faster regardless of whether the app is integer or floating point intensive. In fact, an Athlon is faster even if the Intel CPU is clocked at a higher rate. Here, I'm referring to a P3.

Turns out that Athlons are faster than the new P4 too, even if the latter is clocked at a higher speed. It could be partially because of the lack of GCC optimizations for the P4. See http://www.linuxhardware.org/article.pl?sid=01/07/13/145249 for more info.

5: Response to AMD .vs Intel; GCC et all (response to 1)

Posted by Sam Snow on 07/14/01 04:58 PM

A good source for hardware reviews is http://www.anandtech.com/ -- and they have two articles talking about how their server setup has changed over the years. Interestingly, their current setup is mostly Athlons: http://www.anandtech.com/IT/showdoc.html?i=1456

6: Response to AMD .vs Intel; GCC et all (response to 1)

Posted by Edmund Lian on 07/14/01 05:56 PM

A good source for hardware reviews is http://www.anandtech.com/
 
 
Yeah, but take what is written with a pince of salt. Anand does well at benchmarking, but his lack of engineering background shows through now and then--he is absolutely, absolutely wrong on occasion. 
 
Tom at <a href="http://www.tomshardware.com">www.tomshardware.com</a> and <a href="http://www.sharkeyextreme.com">www.sharkeyextreme.com</a> are generally much more reliable and accurate. They don't over as many boards etc. though.

7: Response to AMD .vs Intel; GCC et all (response to 1)

Posted by Pascal Scheffers on 07/15/01 03:16 PM

I've been running AMD hardware since 1994 or something. The only problem AMD used to have was floating-point speed. Games suffered, so Celerons sold much better than AMD-K5/6's. However, in my experience, I've always had faster 'desktop' (read Word, database, etc) performance. The new Athlon/Duron cores do have very efficient FPUs, so games run excelent on AMD hardware (if that is your poison). A part of the reason for that is the cheaper CPU allows you to buy more RAM. I had twice as much as my friends :)

On the remark on Athlon out performing the P4 at the same speed, that is mainly processor design, the P4 has a 20 steps deep pipeline, the Athlon has 7 or 8. A deeper pipeline gives you higher clocks, but also a higher price when a branch prediction failes.

If you really want to see good writing on CPUs go to arstechnica.com, 'Hanibal' knows what he is talking about.

8: Response to AMD .vs Intel; GCC et all (response to 1)

Posted by Edmund Lian on 07/16/01 03:26 PM

Oh yes, I did forget about Arstechnica... that is a site, thanks. I didn't mention the causes of the P4 throughput issues because there are many, and it's a bit much to get into here...

9: Response to AMD .vs Intel; GCC et all (response to 1)

Posted by Edmund Lian on 07/16/01 03:35 PM

"that is a site" --> "that is a great site" Oops.