Confused about processors

Hi guys, I had a read of Chris Yano's excellent laptop buying guide and read that bit on processors, but I still have a question or two.. Being more familiar with macs, I'm a little confused about the reputation and hierarchy of the various PC laptop processors.

The computer I was planning on buying used is the ThinkPad T40, which has a Pentium 4 M processor. However, I was advised by someone that these processors are know for being both heavy and real energy hoggers. Is this true?

Someone suggested I look at Pentium Ms instead, and someone else mentioned Celeron. I've seen a couple such machines around that meet my needs and budget, but some of them are actually advertised as having a slower GHz than the T40 (The T40 is at 1.5GHz, some of the Celerons and Ms are between 1 and 1.4, I think). How would one of these processors compare to the 4M? One particular machine I've seen that I'm interested in has a Celeron 1.6Ghz. Would this be much faster than the P4M 1.5Ghz?

Thanks guys.

 

The Pentium Ms and Celeron Ms perform faster than they look, they are much more efficient than Pentium 4 processors. Yes, Pentium 4 processors are real energy hogs. The Celeron 1.6 ghz will be significantly faster than the 1.5 ghz Pentium 4. I recommend you get either a Celeron or Pentium M processor.

These may have lower clock speeds but are faster than they look. A 1.0 ghz Pentium M for instance will be at least as fast as a 1.5 ghz Pentium 4 for instance and use significantly less power as well.

I can tell you that the Celeron M 1.6 ghz will be as fast as at least a 3.0 ghz Celeron on a desktop though I don't think Celerons ever got that fast.

 

I think the general equation for comparing mobile processors with their desktop equivalents is to multiply pentium and celeron m's by 1.8 and core duo's by 1.6

 

The newer processors are more efficient, so they don't need the higher clockspeeds like the P4 did. I would avoid P4's as much as possible.

 

Thanks guy. So, do you think this machine (when you go to this link, you have to click on the second picture from the left, the one with centrino logo):

http://www.lapteck.com/tosh.htm

would be quicker and last longer than this one...

http://www.lapteck.com/ibm.htm

 

The Pentium III is even more outdated than the Pentium 4.

I would go with a Core Duo, or better yet, a Core 2 Duo. Even if you pay a bit more money, it won't be outdated for a while (compared to those chips, which are already years outdated).

 

The latter one has a Pentium 4 Mobile at 1.5GHz? If so, anything else made in the last 4-6 years should be faster...

 

Fren, it's not the P111. You have to click on the second laptop image from the left to get to the one I'm talking about. It's a Toshiba Tecra TM1 with a Pentium M Centrino running at 1.4Ghz. Would this be better than the 1.5Ghz Pentium 4 M?

 

Let me put it like this. The PC I bought back in 2000 was better than a 1.5Ghz Pentium 4 M.

Yes, the Pentium M (not 4) would be, at a rough estimate, twice as fast.

It's the difference between a good (but not amazing) CPU that does everything you need, and then, well, a piece of junk.

The P4 had only one strong point. It was able to reach high clock speeds (close to 4GHz). That allowed it to compensate for the worst of its horrible inefficiency. So a 1.5Ghz version? Worst of both worlds. Inefficient as hell, and doesn't even have good clock speeds to compensate.

 

Thanks Jalf for the help, that really clears things up. Could I just ask one more question to you or anyone else - where does the Celeron come in to all of this?

 

You'll see many revile the Celeron, look upon it in disgust, at least I do.

Well, the Celeron M at least is a pretty good processor, it is basically really a stripped down Pentium M processor with about half the cache and no speed stepping capability, that means it always runs at full blast unlike the Pentium Ms which can throttle down to save battery life and emit less heat and fan noise when you don't need as much CPU power.

I had read somewhere on these forums that a Celeron M will perform roughly twice as fast as a regular Celeron at twice the clock speed. That means that a 1.2 ghz Celeron M will perform as fast as a regular 2.4 ghz Celeron.

Oh and the 1.4 ghz Pentium M will be WAY better than the 1.5 ghz Pentium 4. Not only quite a bit faster, but more efficient, more battery life, etc. Avoid the Pentium 4 really.

If you didnt know already, the "Centrino", is not a processor but rather a brand. A laptop that says Centrino only means that it has a Pentium M processor and Intel wireless card, you need both for a machine to have the Centrino sticker. If a laptop has a Pentium M sticker, then it has a wireless card made by another company like Broadcom or Atheros. In my experience, both Intel and non-Intel wireless cards have performed extremely well, though many will say that non-Intel wireless cards are better, always support the underdog right?

You'll always see Centrino commercials in print ads and television because Intel of course want you to buy their processor and wireless card but I say you can't go wrong with either an Intel or non-Intel wireless card.

Anyways, good luck on your purchase.

 

Cheers. I have one final question:

Would you guys advise going for the Pentium M 1.4Ghz as descirbed on page one of this thread, or for a 1.6Ghz Celeron M? The Celeron M seems to be the chip of choice in many bottom-of-the-line PCs right now (Dell use it), but the impression I'm getting from what you said above rahul is that the Pentium M is preferable?

 

Celeron = Cheap

It's the name Intel uses for the "stripped down" versions of their CPU's.
So you have Pentium M Celeron (or Celeron M), which is an inferior version of the Pentium M (So at least it's based on a good CPU),
and you have the Pentium 4 Celeron, which is a cut down version of the Pentium 4. In other words, a crippled version of a CPU that wasn't much good to begin with.

If you're on a budget, Celerons might be worth it, but I'd stay away from the Pentium 4-based ones no matter what.

If you can afford it, always go for the non-Celeron regardless of clock speeds. (So yeah, I'd go with the 1.4GHz Pentium M rather than the 1.6 Celeron)

Only use Celeron if you can't afford anything else

 

I would also recommend the 1.4 ghz Pentium M over the 1.6 ghz Celeron M. The Pentium M has twice as much cache and has the speedstep capability.

 

The Pentium M can do more per clock cycle than the Pentium 4, so for the same performance, higher clock speeds are not required, and this saves incredible on battery life.