Is Hyperthreading P4 worth it for a "second" home box?

[by]

Hello, ladies and gentlemen:

I have been spoilt by how smooth dual-processor linux boxes
can be since 1995 (I splurged on a pair of PPro 200's, with a Orion
chipset board and a whopping 256MB of interleaved RAM!). Since I'm
often doing several things in the background, some of them very CPU
intensive, I often have more than one computer around.

I am considering an HT-enabled P4 for a shuttle (or another
small form factor) box as my secondary PC when I move this summer.

However, an Pentium 4 2.4C (2.4GHz with 800 FSB) costs $170
while a Athlon 64 2800+ costs $187 (both retail from NewEgg). The
motherboard and RAM costs are comparable. I am not asking for any
earth-scorching speed, but I can have a lot of browser windows and
an assorted amount of other stuff up including graphics at once.

Is a HT-enabled P4 a good investment in my situation? Does
it help much on the responsiveness? How long should this Linux box
be good for? For reference, I have purchased dual PPros (180, 200,
200), dual P2/P3's (333, 400, 500, 550, 800), dual celerons (300),
and dual Athlon MPs (1.2GHz, 2000+) for office, server and personal
use for myself and others. On average my equipment lasts 4-5 years
before it is retired (except the monitors).

Thanks for any comments/suggestions.
B.Y.

 

[Steve Wolfe]

I have been spoilt by how smooth dual-processor linux boxes

can be since 1995

Is a HT-enabled P4 a good investment in my situation? Does
it help much on the responsiveness?

Not really. It's nowhere near the same as having two CPU's. Under some
situations, you'll get a small performance benefit from HT, but not under
all. You certainly don't have twice the CPU cycles to use up.

There are other benefits to duallies - while a CPU is busy handling
interrupts, the other can be doing something useful. And, if you have the
same number of apps but two processers, the number of context switches
*per processer* can be lower, assuming your OS does a good job of
scheduling.

I'm a big fan of duallies myself, but it should be said that (A) they're
a LOT more expensive, and (B) aren't the best choice in every situation.
Given the needs that you mention (lots of browser windows, etc.), I'd
guess that the performance boost from the duallies probably wouldn't
justify the cost increase, but of course, that's a judgement call, and
only *you* can make it.

If it helps any, my work machine is a dual AthlonMP 1800+. There are
things I do on this machine that simply make a single-proc machine
unusable, even a fast single-proc machine. At home, I have an AthlonXP
2500+. For the things I do at work, the dually makes much more sense, and
was well worth the cost. However, for the things I do at home, the
single, faster, cheaper chip does a much better job, and a dually probably
would have just been wasted money.

steve

 

[General Schvantzkoph]

Hello, ladies and gentlemen:

I have been spoilt by how smooth dual-processor linux boxes
can be since 1995 (I splurged on a pair of PPro 200's, with a Orion
chipset board and a whopping 256MB of interleaved RAM!). Since I'm
often doing several things in the background, some of them very CPU
intensive, I often have more than one computer around.

I am considering an HT-enabled P4 for a shuttle (or another
small form factor) box as my secondary PC when I move this summer.

However, an Pentium 4 2.4C (2.4GHz with 800 FSB) costs $170
while a Athlon 64 2800+ costs $187 (both retail from NewEgg). The
motherboard and RAM costs are comparable. I am not asking for any
earth-scorching speed, but I can have a lot of browser windows and
an assorted amount of other stuff up including graphics at once.

Is a HT-enabled P4 a good investment in my situation? Does
it help much on the responsiveness? How long should this Linux box
be good for? For reference, I have purchased dual PPros (180, 200,
200), dual P2/P3's (333, 400, 500, 550, 800), dual celerons (300),
and dual Athlon MPs (1.2GHz, 2000+) for office, server and personal
use for myself and others. On average my equipment lasts 4-5 years
before it is retired (except the monitors).

Thanks for any comments/suggestions.
B.Y.

Hyperthreading is only a marginal improvement in the best of circumstances
and actually hurts performance in many circumstances. I have it turned off
on my dual Xeon box. An Athlon XP2800 will outrun a 2.4GHz P4 with or
without hyperthreading. You might want to wait a month for the 939 pin
Athlon64FXs to come out. You could also buy an Athlon64 or Opteron 1xx
based board today. I wouldn't buy an AthlonXP board now, they are
obsolete. The new Nforce3-250 (not the older -150) based Athlon64 boards
look interesting, but I'd wait to see how the 939 (vs 745) pin parts and
motherboards are priced.

 

[Henrik Carlqvist]

However, an Pentium 4 2.4C (2.4GHz with 800 FSB) costs $170
while a Athlon 64 2800+ costs $187 (both retail from NewEgg). The
motherboard and RAM costs are comparable.

So you are choosing between HT or 64 bits then.

You are already aware that HT will not give you a true 2 CPU SMP system,
in some lucky situations it might be able to give you a 1.5 CPU SMP
system. If you are really unlucky the performance could even be worse with
HT enabled.

If performance is important, try to find a benchmark which is
representative for your work and ask people with machines resembling the
ones you are considering to run that benchmark.

When I recently bought a new computer I did choose a P4 2.6 GHz with HT.
I don't think that this CPU is better than an Athlon 64, but I had more
confidence in my motherboards chipset (i875p) than chipsets from VIA and
nVidia which is common on athlon motherboards.

regards Henrik

 

[Nate Edel]

Not really. It's nowhere near the same as having two CPU's. Under some
situations, you'll get a small performance benefit from HT, but not under
all. You certainly don't have twice the CPU cycles to use up.

Unders some situations, it can add up to a moderate benefit, not just a
small one.

Given the needs that you mention (lots of browser windows, etc.), I'd
guess that the performance boost from the duallies probably wouldn't
justify the cost increase, but of course, that's a judgement call, and
only *you* can make it.

The big thing that helps with lots of browser windows, besides a faster
internet connection is lots of memory.

 

[ByteEnable]

Here are some real numbers for you.

http://www.linuxelectrons.com/article.php/20040226231747944

 

[chrisv]

The big thing that helps with lots of browser windows, besides a faster
internet connection is lots of memory.

But indispensable, for some of us. 8) And someone with a Celeron
400 and high-speed Internet rules over someone with a fancy new rig
and dialup. 8)

 

[chrisv]

Not really. It's nowhere near the same as having two CPU's.

I've never had a dual CPU box... May be fun to try it, with a pair of
Athlon 64's (or whatever they're calling them nowdays)...