CPU cache

[Force Flow]

Say you have two idendical CPUs, except one has a 256k L2 cache and the other has 512k. Would there be a noticeable difference.

Also, what exactly is L1 and L2 cache?

[juppy]

I don't know if it would be noticeable to the naked eye, but it should show up in benchmarks. The chip with the larger cache should be faster because it can hold more of the commands in the L2 memory and not have to totally go back and reload them from the disk when it needs to reuse it again.
The L1 cache is the memory cache that holds all the basic commands. I think these came out on the 486 first (not sure).
The L2 is basically like the L1 except it just holds other commands and frequently accessed info that the chip may need later, thus speeding up the processing. The L2 cache used to be on the mobo itself as a row of chips. You could actually buy more L2 cache memory to install in your machine. Later on they soldered 'em to the mobo and later yet they finally put them on the cpu itself.

[Force Flow]

Thanks juppy

[Alienware_Dude]

Technically, L1 cache is SRAM that is located directly on the CPU die, and L2 cache is SRAM which is located off of the CPU die, at least that's the way it was. Nowadays, both L1 and L2 cache are located directly on the CPU die, allowing them to run at full-core speed(the clock speed of the processor). L2 cache that was located in the processor package but not directly on the die usually ran at half/one-third core speed when the core speed got to high for the SRAM that was being manufactured. As far as I know, there is no difference in what the L1 cache holds as compared to L2 cache, except that the processor looks first in the L1 cache to find what it needs. Some server boards have what is called L3 cache, which is usually located on the motherboard. I know that the dual-CPU G4s have this.

[DHB]

don't want to start a fight, but from the test reports i have read you probably won't see that much of an increase in benchmarks, the extra l2 cache only comes into play if you are doing intensive tasks that require alot. (i'm explaining this bad) but basically in doing normal tasks in word or wotever the amount of processing that is needed is minimal and so the extra l2 cache is never needed it only comes into play when your doing video editing, encoding, and stuff like that, and so you will only see an increase in benchmarks if the program is using large enough test data that requires the extra cache. (well thats the impression i get from wot i've read)

[Force Flow]

Okay, say you're running progs like photoshop, premiere and lightwave. Would you notice a difference between a 256K and 512K cache?

[Cricket]

Originally posted by force_flow2002
Okay, say you're running progs like photoshop, premiere and lightwave. Would you notice a difference between a 256K and 512K cache?

Yes, you'll see a noticeable difference.

Cricket

[Force Flow]

So it would be benifical to get a CPU with a large cache, then.

[Cricket]

A "power-user" should get a P4 or Athlon XP.

People who use their computers for mundane things like surfing the web, checking e-mail and writing letters with a word processor can easily get by with a Celeron or Duron.

Cricket

[Force Flow]

I kind of thought that's what the general consensus was. Thanks Cricket

[avx]

I know you pretty much already understand ForceFlow...But Im taking this PC class, and this book has been useless except for a few good references, and a few good definitions. So Im gonna go ahead and give the definition put forth by Peter Norton himself Something funny I think I should mention though, they dont mention L1 or L2 cache through the whole book...If it wasnt for my Instructor I never would have understood that this is what they meant in that part of the book.

Because all computer data is stored as numbers, much of the processing that takes place involves comparing numbers or carrying out mathmatical operations. In additioni to establishing order sequences and changing those sequences, the computer can perform 2 type of operations: arithmetic operations and logical operations(L1 and L2 cache). Arithmetic operation include Addition, subtraction, multiplication and division(L1). Logical operations include comparisons, such as determining whether one number is equal to, not equal to greater than, or less than another number.

Since they dont actually list which is which, and Im just going on a faint memory of how Dan described it, I could have the backwards, if so someone please correct me. Im just trying to get some use out of this book I paid 50 bucks for