Intel Celeron 566 (1/7)

Let me say a few words before we start. I saw a lot Celeron 566 reviews on the web overclocking this baby to 100MHz / 112MHz FSB or more. So many people might think all 566 can run with 100 without any trouble at all. But you should´nt get the impression that this is true for all 566 CPU´s out there. Maybe you´re lucky, maybe you´re not! We had a very critical 566 for our review.

Since its introduction, Intel's Celeron line of processors has enjoyed enormous popularity. Overclockers are especially fond of it for its great value. Celerons are very overclockable and offer good performance at a moderate price, and great value is what overclocking is all about, right?

The original Celeron is really a Pentium II with 128KB on-die second-level cache running at full processor speed. Up until the old Pentium III 600, the 512KB off-die cache ran at half the speed of the processor core. Starting with the Coppermine family (E or EB suffix), it was brought on-die and runs at full speed as well, although it has been reduced to 256KB. The new Celeron (II) is based on this new Coppermine core including all of its new SIMD instructions (ISSE), but still using only 128KB cache. Unfortunately, one thing hasn't changed: Intel is still limiting the Celerons to a 66MHz FSB.

Overclocking only started to become widespread with the introduction of the legendary Celeron 300A. It's a well-known fact that Intel clock-locks its processors, meaning that the multiplier is set to a certain value and can not be changed. The Celeron 300A's multiplier is set to 4,5. The final clockspeed is determined by multiplying the FSB by the multiplier. In this case 4,5 x 66MHz = 300.

The new Celeron Available at 600, 566, and 533 MHz Dynamic Execution technology Intel MMX ™ media enhancement technology Intel Streaming SIMD Extensions (ISSE) (only for 533A, 566, 600 and above) 32 Kbytes (16 Kbytes instruction/16Kbytes data) Level 1 cache 128 Kbytes integrated Level 2 cache 66 MHz Intel P6 microarchitecture multi-transaction system bus Packaging: Flip-Chip-Pin-Grid-Array (FC-PGA) Bus Speed: 66 MHz Voltage: 1.5V Wattage: 18W Die Size: 1.046 cm² Addressable Memory: 4 Gigabytes CPUID: 068x

If you set the FSB to 100 instead, you got that same Celeron running at 450 MHz. Overall there was a 50 % chance that your then brand-new Celeron was able to run at that speed. I am the proud owner of two such chips, both of which I run at 464 MHz (103 FSB) in a dual-processor mainboard with the help of smp-enabled Tekram S370->Slot 1 converter cards.

Reaching 450MHz was very nice indeed, but what the old Celerons still lacked was the PIII's SIMD extensions. Fortunately, that problem has been solved! The new Celerons use the Coppermine core, giving them not only the SIMD instructions but the new optimized cache and pipelines. The only things setting the Celerons apart from their "big brothers" are the smaller second-level cache (128KB) and the 66MHz FSB.

Our Celeron 566 with a Global Win FKP32 cooler on a Tekram P6TS3 FCPGA/Slot1 adapter card

Our goal was to find out how well this new crop of "Celery" really performs. The 566 is a particularly tempting offer, since its 8,5 multiplier could mean overclocking to 850MHz on a 100 MHz FSB - not bad value at all for about 350 German Marks! Besides, 850MHz isn't too high an expectation to make it a completely unrealistic goal. Well, in theory anyway.

Unfortunately, that's just what it is - theory. Encouraged by some reviews I had read on the web I went out and bought a good heatsink/fan combo from cooling specialist Frozen Silicon. The Global Win FKP32 moves a lot of air - and makes a lot of noise! But that's the price the overclocker pays for good results - good cooling is essential!

Mainboards based on Intel's BX chipset still represent the best and most stable platform for overclocking. They are fast, mature, and free of any driver/chipset problems. Since most of these boards still ship with a Slot 1 configuration, you'll need a "slotket" adapter card. Unfortunately, the old "slotkets" can no longer be used with the new Celerons, since Intel changed the pin-out of the FCPGA Coppermine core. So you need to make sure that your "slotket" is FCPGA-ready. I used a Tekram "slotket", which has been FCPGA compatible since revision 2.01 and supports the necessary voltage of 1.65V.

Due to its size, the heatsink/fan combo blocks the memory expansion slots on the mainboard. Fortunately, this problem can easily be solved by reattaching the fan a bit higher up on the heatsink. (No problem at all: remove one clip and put screws into the heatsink through the fan's mounting holes).

Copyright: 16.06.2000 (Tanslation by Benjamin Kraft)-   RIVA Station 2000 - Lars Weinand
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