Originally posted by eddy05
Which is faster? the L1 or L2 cache? presuming they are running at full speed instead of half speed. Both P4 and Athlon XP.
Originally posted by guyferd
I guess L2 cache is faster than L2
L2 cache, just like any other cache, acts as sort of a middle man between two mediums, in this case, your CPU’s L1 cache and your system memory (as well as other storage mediums). When the CPU wants to request a bit of data, it first searches in its L1 cache to see if it can find it there; if it does, then this results in what is known as a cache hit and the CPU retrieves it from the extremely fast, low latency L1 cache.
If it can’t retrieve it from L1 cache, it then goes to the L2 cache where it attempts to do the same – obtain a cache “hit.” In the event of a miss, the CPU must then go all the way to system memory in order to retrieve the data it needs. With the L2 cache of today’s CPUs operating at a much higher frequency and at much lower latency than system memory, if the L2 cache weren’t there or the cache mapping technique wasn’t as effective, we would see considerably lower performance figures from our systems.
Smaller caches are faster, so often a small level 1 cache is used, with a larger but slower level 2 cache supporting it. Level 3 caches can even be used in some cases.
A processor’s cache memory usually consists of L1 and L2 caches. The L1 is located within the processor’s core, and must have a very low latency as it is used extensively for all sorts of purposes, such as data fetching, data shifting and data loops, storing only small amounts of data. The L2 cache, either located on-die or external, stores much more data, coming usually from the L1 cache in multiples of the L1 cache size. An frequent L2 cache configuration is between four and sixteen times that of the L1, depending on configuration and desired latency.
The biggest advantage of moving the L2 cache on-die and running it at full clockspeed is that both the L1 and the L2 cache can run in parallel and be accessed concurrently, reducing latency. This is a good way to improve cache performance, but it also has a couple of disadvantages. One is that tuning for higher clockspeeds with a reduction in latency also reduces the potential cache memory clockspeed.
DaProffessaT34 said:L2 is. If you compare I think it is L2 cache.