Which setup performs better for hosting php/mysql sites?

Dual p3 handles loads better

My experiences with a dual p3 866 mhz coppermine system is that they're not stable, in comparison to a single p4 anyways.

The dual setup will outperform the P4 for PHP / MySQL related sites. We have no stability issues with our dual P3's, and the high end P3's ( 1.13Ghz +) absolutely fly.

How would you think of comparing the following:

Dual 1.4 PIII
Single 1.4 PIII ?

Would you see a GREAT deal of performance increase, i.e twice performance? Or would it be comparable to like a single 2.2Ghz for example

How about

Dual 1.4Ghz PIII
Dual 1.8Ghz IV
Dual 2.0Ghz IV

Would you think of seeing much difference in performance?

I have dual 1.13P3 and a single 1.9P4, and the P4 seems to outdo the P3 in speeds e.g. apache recompile etc, but the dual is better for big forums etc, that require PHP and MySQL heavily.

You wouldn't see twice the performance increase even though in theory you have twice the processing power, however when you have multiple apache requests, and many applications demanding CPU time, that's when you'll reap the benefits of the 2nd processor.

I guess it would be best to take the middle dual setup - the P4 1.8

I'd choose the dual P3 1.4 over either of the dual P4's, unless they were Xeon's, personally...

Can I ask what your reason is? Performance?

I use all dual P3 1.26 for this very reason... most bang for buck.

When it comes down to it, it depends on your operating system and software.

Is your web site the kind that benefits from dual CPU?

In my case, sometimes I run a database on the same server as the web site... and if the web site has a bug in it (bad PHP or ASP) and goes into a loop, at least the other CPU is free.

I've run the same site, mirrored at two different ISP's, and identical system... one with single CPu and one with dual. Despite averaging only 20% of the single CPU... I have a lot more problems when things get borked.

Dual better for servers IF your operating system and application can deal properly with them. Sometimes wierd concurrency problems show up on DUAL that don't on single.

ASP.NET (dotNET) also uses more RAM and has limits on SESSION capability on multi-CPU systems that don't exist on single CPU systems...

Ok, so the conclusion is, that dual p3 usually performs better in case of php / mysql.

By the way, I don' t think there are any dual p4, only dual xeons.

I'd go for the dual p3's !

One thing you should research is I have heard P4's are not really as fast as they are labeled. That is why AMD started using confusing labeling on their processors (Ie.. an Athlon XP 1700 is not 1.7Ghz, it's 1.47Ghz. They named it the "1700" because it supposedely competes with a P4 1.7Ghz).

For example, i don't believe a 2GHZ p4 is "twice as fast" as a 1GHZ p3. Anyway, I'm not really a hardware guy, I've just been told this by some other hardware guys. :D It may be good to do a search for p3 vs p4 on google.

One more thing - some of the p3 chips above 1GHZ have 512k cache instead of 256k. (I think these are the chips that were meant to be used in servers). Anyway, they cost a little more, but perform way better.

I'd go for a dual p3 1.4Ghz with 512k cache. That system would scream! :)

One more thing..

If you want dual P3's... by far, the best motherboard I found was the Intel SCB2.

I got 6 of these sytems, all 1u... from QSol. QSol lets you specifc the SCB2 as an option.

Takes a ton of RAM, 3 hot-swap hard drives, 1u footprint. Solid system.

Using dual 1.26's in all 6 servers. Some running SAPDB and some running web sites / custom applications.

Cheap and good. Not fancy, but solid!