SSE 2 Instructions Set

   Intel introduced the MMX (MMX for MultiMedia eXtensions) instructions set back in 1996. This was the first instruction addition to the x86 architecture since the i386 was released. Remember, the MMX instruction set was full of multimedia dedicated features that were here to accelerate applications which used them. MMX applications came a bit later on the market but most users enjoyed MMX benefits especially in games since game developers adopted them quickly. More recently Intel added SSE (Streaming SIMD Extension) to its Pentium III: this was a set of 70 supplementary extensions that used the SIMD (Single Instruction Multiple Data) technology just like the MMX or 3D Now (From AMD). SIMD principle is simple: it should treat only one pass of several data with only one instruction. Compared to a standard SISD x86 instruction (Single Instruction Single Data) where one instruction should give one result the SSE can give up to 4 results in the same clock cycle. 

The SSE instruction set principally enhances audio and video compression processes as shown by our tests: indeed compressing an audio file of 130 MB took 8.5 seconds against 10.3 seconds using a Pentium III 1 GHz: for this kind of task the Celeron could boost performance up to 28%. SSE 2 brings several enhancements dedicated to boost MPEG 2 encoding and file encrypting processes. First it adds 144 new instructions (oriented on memory and cache management) to the SSE & MMX existing ones but it can now handle integers of 128-bit numbers (1 per cycle), and double precision floating of 64-bit (two per cycle). Just like the MMX the SSE 2 set of instructions is no use if you don’t have compliant applications that take benefit from it: hopefully most of today games and video mounting software (for example) as well as Microsoft Direct X 8.0 API use SSE2 instructions.

Intel Celeron 1.8GHz CPU Design

The Intel Celeron 1.8GHz architecture has nothing new. Indeed the processor uses the same old good Willamette core, which the Pentium 4s were using, until recently. Many of you would have surely prefer Intel to use the northwood 0,13µ core for the Celeron in order to have more overclocking facilities, but Intel has still a lot of 0,18µ facilities they need to make profitable.  Therefore engraved in 0,18µ, the Intel Celeron 1.8 GHz comes in the same µPGA Socket 478 package than modern Pentium 4, and uses a 1.75v core voltage. This choice is logical and helps Intel achieves the whole conversion of its processor range to using a single socket. This move is especially clever since OEM will have the opprotunity to build main stream computer that can be later upgraded by replacing the Celeron with a Pentium 4 processor. Not to say that OEMs will have a wide choice of chipsets that support every imaginable flavours of memory.  

So you might wonder how an Intel Celeron 1.8 GHz processor differs from a Pentium 4 1.8 GHz (Willamette)? Well the answer is quite simple: the L2 cache memory of the Celeron has been trimmed down by 50% in comparison to the L2 cache memory of a Pentium 4. So Intel’s new Celeron 1.8 GHz processor embarks only 128 KB of full speed L2 cache memory. Thus at equal frequency a Celeron Willamette will be slower than a Pentium 4 Willamette. The Intel Celeron 1.8 GHz uses the famous 400 MHz quad pumped front side bus (4x100 MHz) delivering an amazing 3.2 GB/s bandwidth. 

When Intel introduced the first Celeron processors, the non-marketed feature was the fact these processors were safely overclockable by up to 50%. This situation is now over. The Celeron 1.8GHz processor can be overclocked, almost safely, by up to 20%. Anyhow overclocking your processor will void warranty and most likely render your system unstable so this practice isn’t advisable.