Put simply: Pentiums have bigger caches and a faster front side bus, which means better performance The only advantage of a Celeron is cost
Cache Cache (Static RAM) is similar to the memory you normally put into your computer (Dynamic RAM), except it is located on the processor itself. This makes the memory very fast to read/write, so it's like 'super RAM'. This cache is not used to store general program information such as your Microsoft Word text document. Instead, the cache is used to store critical (and frequently accessed) operating system information. Cache is much more expensive to produce then dynamic RAM, hence you get a lot less of it. For example, a typical Pentium 3 system would have 256MB (megabytes) of RAM, but only 256KB (Kilobytes) of Cache. Front Side Bus speeds I'm sure you are familiar with CPU clock speeds. For example, it's obvious that a Pentium 4 1.7GHz is going to be slower then a Pentium 4 2.5GHz. However, it is not as obvious as it seems. CPUs also have an external clock speed. This is the speed at which data leaves the processor, and travels around the motherboard. Your CPU's external clock speed must be sync'd to your motherboard speed, and memory speed. For example, If I choose to buy an AMD Sempron 2400+, I know that the external bus speed is 333MHz. I need to make sure that my motherboard also runs at (supports) 333MHz, and my RAM also. Therefore I shall buy PC2700 DDR RAM, which runs at 333MHz. A typical Pentium 3 would be marked as 700/256/100/1.75v. That means it runs at 700MHz (internal clock), has a 256KB cache, and a FSB (front side bus) of 100MHz. A typical Celeron manufactured around the same time would be 600/128/66/1.75v If this doesn't make sense, or you want me to elaborate further, just ask
Static RAM (SRAM) also does not have to be periodically refreshed like DRAM does. While this is nice, it ain't cheap, and is a big reason why you don't see SRAM available in the same quantities as DRAM (DDR, DDR2, Rambus). I don't know about you, but I doubt there'd be too many people clamoring to spend $2k on a 256MB stick of RAM.
The one clear cut advantage of Celerons is they function better as laptop chips in that they draw less power, so you'll be graced with more battery life. What you'll actually get done with that extra battery life however if up in the air.
L1 cathe - which comes with motherboard. L2 catche - External Catche.......comes with Hard disks etc.
Wikipedia definition. L2 cache nowadays are on the CPU die itself, it used to be that you could buy more cache externally but not so anymore. Info about CPU cache.
The Level 2 cache on older Pentium 1 systems was located on the motherboard. Some of these older motherboards had a COASt (cache-on-a-stick) socket, where you could insert some extra cache RAM. Since the Pentium 2 however, Level 2 cache is located on the processor (or on the daughter card for a Slot 1 CPU). Have we forgotten about Level 3 cache? Located on the motherboard to supply extra cache space. Not as fast as Level 1 or 2 cache
