Comparison

[JimL]

It's kind of hard to find a category for this...

On eBay I've seen T30's and T40's for sale. The T30's list an average CPU speed somewhat higher than T40's. That is, T40's seem to be almost always 1.5G while T30's run 1.8G and 2G.

Is this normal - to be expected? Or is it some sort of mass coincidence?

[Thinkpaddict]

It sounds like T30s must be running Pentium 4 at higher clock rates. However, a Pentium M (T4x) will be faster than a Pentium 4 (T30), even if the Pentium 4 runs at higher clock speeds. It is just a different architecture. To put it simply, the Pentium M does more work in each clock cycle, so it will do more work even at lower frequencies.

[jdhurst]

A 1.4 GHz PM T41 (I have one) is faster and cooler than a 2.0 GHz P4 T30 (I had one). I recall asking the same question here 30 odd months ago. ... JD Hurst

[agarza]

To put some comparison:

Using Super-Pi, a software which calculates the pi number, telling the CPU to calculate that number to 2 million digits I got:

Thinkpad T30, Pentium 4-M @ 1.6GHz --> 4min05s
Thinkpad T42p, Pentium M @ 1.8GHz --> 2m05s

Numbers say it all

[pianowizard]

Even a Pentium III processor is faster than a Pentium 4 processor of the same clock rate. I read somewhere that the fastest PIII (1.4GHz) is about as fast as the 1.7GHz P4.

[Thinkpaddict]

That's right, the Pentium 4 architecture was a step back for Intel. I suppose they intended to make up for its shortcomings by sheer brute force (increase of CPU frequency), but that approach didn't quite pay out.

The Pentium M is more similar to the Pentium 3 than to the Pentium 4.

[cLOWN gOD]

ok, but in that example, the T40 had the faster clock rate. Isn't that to be expected??

[doppelfish]

ok, but in that example, the T40 had the faster clock rate. Isn't that to be expected??

Well, I wouldn't expect a ~10% higher clock to almost double the crunching rate.

cheers,
-- fish