dual-core, ht, l2

[Andersen]

In general, which of these boosts "overall" performance of a computer
(multitasking, office, xp pro, etc... not a gamer):

memory: 1024mb mem vs 512mb
cpu: dual-core vs hyperthreading
L2 cache: 1mb vs 2x1mb vs 2mb

 

[kony]

In general, which of these boosts "overall" performance of a computer
(multitasking, office, xp pro, etc... not a gamer):

In general, there is no overall, it's per use, not "etc".
Grandma X can seem like a light user, then she scans in an
8.5x11" photo at 1200dpi and moderately edits it. She may
need more than a gamer for this task but the rest of the
time she only does email and websurfing. Each task
requirement and frequency of the task has to be considered
to determine if the cost of the upgraded spec is worthwhile.

memory: 1024mb mem vs 512mb

Depends on memory load, check Task Manager if it's windows.

cpu: dual-core vs hyperthreading

Depends on use, usually neither of these are nearly as
effective as a good ole single core running at higher clock
speed or at least higher IPC.

L2 cache: 1mb vs 2x1mb vs 2mb

Depends on the app, for most common "PC" uses 1MB is enough
L2, anything more is enough of a diminishing return that
most other variables matter more.

In general, one does not choose one or the other, they
choose the system budget and won't try to buy one part to
offset the rest of the system. If it's a low end PC running
XP, 1GB of memory is overkill. If it's a high end gaming
system, 512MB is underkill. You don't even mention the hard
drive, for the uses you just mentioned it is more important,
but perhaps memory second if you heavily multitask.

 

[Paul]

In general, which of these boosts "overall" performance of a computer
(multitasking, office, xp pro, etc... not a gamer):

memory: 1024mb mem vs 512mb

The OS operates with "virtual memory". If all the physical
memory is used, the hard drive is used to extend it. And
you don't want that to happen. Thus, you have to gauge your
own usage patterns, and have to know the characteristics of
the programs you use, in order to know how much memory is
enough.

For office apps, used one at a time, 512MB might be enough.
You might hear the odd creak and groan from your system.
With the low cost of memory, having 1GB wouldn't hurt.
Both my currently in use PCs are 1GB and I have no complaints.
Last time I checked, max fill was 700MB while gaming.

cpu: dual-core vs hyperthreading

You should compare: single core w. no hyperthread
single core w. hyperthread
dual core

Only the first option, would give you a slightly less
smooth and responsive desktop (like tiny fraction of
a second delays). At least, that is my experience.
If there is a lot of multitasking going on, then either
of the latter two options gives a slightly nicer user
experience.

With hyperthreading, you are milking the last 10% of
performance from the CPU. And depending on the
applications in use, hyperthreading has been known to
actually reduce performance (thrashing). Basically, while
the processor is blocked working on the current thing,
you can attempt to execute a bit of some other work.
It is like a dual core, with extremely restrictive
internal resource limitations (keeps bumping its head).

If a dual core has a limitation, it is going to be how
the cores are bussed to the memory. With generous cache,
they don't end up waiting too much, at least for instructions.

L2 cache: 1mb vs 2x1mb vs 2mb

512KB per core is enough to get by. Not every application
sees an advantage from extra cache, but like more RAM, if
they are giving it away for free, then take it.

HTH,
Paul