Advantages of more cache?

[moosey]

What are the advantages of more cache, like going from a celeron tualtin 256k cache to a pIII tualatin at 512k cache? Are there any downsides?

 

[imgod2u]

Think of cache as a faster pocket of memory closer to the CPU. The more cache, the better the chance that something the CPU needs is already in the cache and it would therefore be a lot faster to access than something in memory or in HD.

 

[Budman]

Go into your bios & turn off L1 & L2 cache,you'll soon see the advantages of having cache.😉



The more the better.

 

[moosey]

yeah. but how much of a performance diff in games and cd ripping and things like that will a boost from 256k to 512k bring?

 

[AndyHui]

CD Ripping, probably not that much.

Games, heaps. Doubling the L2 cache like that is sometimes worth more than a 10% increase.

 

[imgod2u]

It really depends on the specific setup. A P4 running at 2.5 GHz with a high latency memory subsystem (RDRAM) would improve significantly from an increase in cache size while an Athlon at 1.8 GHz with a low-latency memory subsystem wouldn't improve as much from it. The processor architecture also has something to do with it but there is no definitive number I can give you. Just look at the benchmarks for the P4 Willamette vs Northwood at the same clockspeed.

 

[moosey]

what about celeron tualatin 256k going to p3 tualatin 512k?

 

[dexvx]

More cache is the useful most useful in multi-processor configs. Because you have more cache, the cpu spends less time accessing the system memory (with multi-procs which usually have some kind of shared system memory, teh result can be huge). For instance, Sun Ultra Sparc IIIe's with 8MB cache from 4-8 processor nearly retain a 90% efficiency while Pentium III Xeons with 2MB cache from 4-8 processor configurations are only about a 60% efficiency (based on Aceshardware's average and specINT/FPU performance).

From single processor performance, just look at Willamette Celeron (128KB), Willamettes (256KB), and Northwoods (512KB) at 1.8Ghz, since they're all available at 1.8Ghz.

 

[Goi]

There's definitely be a noticable and quite significant performance difference between a Celeron Tualatin and a P3 Tualatin. Whether or not you notice that difference depends on your pattern of usage. On things that are pure calculational and not memory intensive, you won't notice any difference. For example, both of the above-mentioned CPUs, clocked at identical speeds, will crack rc5 at identical rates. In games, you'll probably notice the difference. The obvious downside is of course price.