laptop computer speed

My cousin-in-law asked me last week what I'd choose between a computer (laptop, actually), with a 1.xGhz CPU and 512MB of RAM and a 2.xGhz CPU with 256MB of RAM. I said I'd choose the first.

I've been monitoring CPU use on the laptop I currently use (icewm makes that really easy, with CPU and network monitors on the taskbar), and I just don't see a lot of CPU peaking. There are occasional peaks when a scheduled rsync job runs (copying data over a vpn from the office to my laptop, cheap remote backup), and when i run xboard+gnuchess. When I test one or another program I'm developing I may see some peaking, and sometimes when I run vmware (not a lot of that though).

Mainly, though, my CPU usage stays pretty low.

I recently finally built a kernel that works well with my mobile AMD CPU and now I'm able to set the CPU maximum speed to a large range of speeds (.66Ghz to 1.7Ghz, plus 6 other speeds in between). I've also got the cpufreq/scaling_governor set to ondemand. The computer pretty much ALWAYS stays at the slowest speed all the time except when running xboard+gnuchess or very occasionally, when something CPU intensive runs. When an application needs more CPU, the CPU speed ramps up immediately, and when it's no longer needed, the CPU slows down to .66Ghz.

From the fact that the scaling_max_freq pretty much stays at the slowest speed except for very short periods, my opinion on which laptop to buy is reinforced. The icewm monitor also displays related information (e.g., how much IO is occurring) and I find that the laptop slows down more due to waiting for IO (well, laptop drives are slow) than due to needing more CPU. So more RAM will help with the IO requirements (the OS can cache more of the disk), speeding up the general experience, more than higher CPU speed.

Actually, his original question had to do with a celeron (or some other internal-cache-challenged CPU) versus a full CPU at the same or a higher frequency. I think that RAM is still more important, generally, than CPU speed.

Of course, if the main use of the computer is going to be for photoshop or corel draw effects or CAD and 3D rendering, then I'd go with all the CPU power I could get PLUS all the RAM I could get. but for general use, even for a software developer like me, any 1.3Ghz box with more memory is probably going to be the better deal than a higher frequency box with half the memory.