Which is Faster? L1/L2

eddy05 · Jun 21, 2002

Which is faster? the L1 or L2 cache? presuming they are running at full speed instead of half speed. Both P4 and Athlon XP.

guyferd · Jun 21, 2002

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.

if you compare L1 & L2 cache for computer speed, I guess L2 cache is faster than L2 because it's like the processor memory, but both L1 & L2 cache are very important for the computer speed.
so i suggest a computer with L2 cache bigger.

SNGX1275 · Jun 21, 2002

L1 is faster and more expensive, thats why you don't see much L1. L2 though is an important step before it actually searches the RAM for it.

eddy05 · Jun 21, 2002

So actually how fast are the cache? I only know L2 cache are as fast as the CPU clock, but how about L1?

Vehementi · Jun 22, 2002

Re: Re: Which is Faster? L1/L2

Originally posted by guyferd
I guess L2 cache is faster than L2

If my knowledge is correct, the L2 cache, which is the backside bus, or BSB (no boy bands here ) is half the CPU clock.

TS | Thomas · Jun 22, 2002

CPUs not really my thing but L1 cache I believe is the same speed as the CPU, most L2 usually only runs at a fraction of CPU speed & can be on, or off die.
L2 cache I think used to actually be part of the motherboard before it was added onto the CPU itself. It's just really fast RAM.

Didou · Jun 23, 2002

It's very hard to find articles talking about cache that aren't 5 years old. At the time, L2 cache was still onboard or on the CPU Socket but not On-Die. There are some info on how L1 & L2 caches work here ->

1. http://www.anandtech.com/showdoc.html?i=1252&p=5

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.

2. http://www3.sk.sympatico.ca/jbayko/cpuAppendC.html

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.

3. http://www.hardwarecentral.com/hardwarecentral/interviews/1465/3/

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 · Apr 17, 2006

L2 is. If you compare I think it is L2 cache.

howard_hopkinso · Apr 17, 2006

DaProffessaT34 said:

L2 is. If you compare I think it is L2 cache.

Why have you posted in a thread that`s almost 4 years old?

Didou · Apr 18, 2006

& on top of that, with wrong information. At least read the previous posts before giving in to your thread necrophilia & replying.

CMH · Apr 18, 2006

Lol, don't you love the nostalgia...

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Which is Faster? L1/L2

eddy05 Newcomer, in training

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