Overclock intel celeron b800: Intel Celeron B800 Overclock Benchmarks

Everybody let’s clock: More power by overclocking

The new AMD Duron has taken away the low-end performance crown from Intel’s Celeron. One important reason is of course the higher Front Side Bus speed of the Duron: It works at 200 MHz (100 MHz double pumped) and 133 MHz memory clock, while the Celeron is restricted to 66 MHz both.

Nevertheless, the Celeron has several advantages, which we explained in detail in the Performance Guide. Most important is of course the better price for both CPU and a decent motherboard. In addition, the Celeron is very interesting for upgrades, thanks to its 66 MHz bus. Of course we will also deal with this topic elaborately.

Freaks know that the Celeron is the perfect overclocking processor, as almost every specimen can be run far beyond its specs, while the whole processor family is usually very inexpensive. Overclocking to front side bus clocks of 75, 83, 92 or even 100 MHz do not cause problems, as today’s motherboards are designed to run at up to 133 MHz front side bus. Almost the only limiting factor is the CPU, which can be regarded as the optimum situation for processor overclocking.

The latest Celeron with the Coppermine-128 core seems to accept the inheritance of the Mendocino. Both models can be overclocked to up to 50% by rising the bus speed from 66 to 100 MHz max. This article will give you all the necessary information and useful hints to make your system running at the limit.

Which CPUs can be overclocked?

Talking about the Celeron, you have to distinguish between the three different cores: Covington, Mendocino and Coppermine. Some years ago, Intel needed a low cost processor in order to compete against AMD’s K6-2 family. The first chip came with the Covington core (Slot-1, 266 and 300 MHz), which was based on the Pentium II Deschutes. This initial Celeron came without any L2 cache, making it a poor performer and rather unattractive.

Only some months later, Intel released the 2nd generation of Celeron processors, coming with the Mendocino core. This one has 128 Kbytes L2 cache on die, running at full CPU clock speed. As most of us should know, this processor is inexpensive and fast. Thanks to the integrated cache memory, it almost reaches the performance of a Pentium II at the same clock speed, even though the PII has four times the cache size (but only running at 1/2 CPU clock). In addition, Celeron’s price tag was and still is much more attractive than Intel’s high-end processors Pentium II and Pentium III. Two years ago, Intel’s yields were already good enough to have most Celeron 300A CPUs running safely at 100 MHz FSB, raising the core clock to some amazing 450 MHz.

The latest Celeron model ist again based on a Pentium core. This time, the core name is ‘Coppermine’ and the differences between the ‘Coppermine-Pentium II’ and the ‘Coppermine-Celeron’ are rather small. Celeron is still officially limited to 66 MHz FSB and it comes with 128 Kbytes less L2 cache. The following table will show you the differences between all Celeron cores in more detail.

CPU core	Covington	Mendocino	Coppermine
Clock speeds	266, 300 MHz	300A, 333, 366, 400, 433, 466, 500, 533 MHz	533A, 566, 600, 633, 667, 700 MHz
Slot/Socket	SEP — Slot 1	PPGA-370	FCPGA-370
Core voltage	2. 0 V	2.0 V	1.5 V — 1.7 V up to 600 MHz 1,65 V — 1,7 V 633+ MHz
L2 Cache	none	128 KBytes	128 KBytes
L2 Cache clock	—	Full CPU speed	Full CPU speed
System clock speed	66 MHz	66 MHz	66 MHz
Multipliers *	4, 4. 5	4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8	8, 8.5, 9, 9.5, 10, 10.5

* Just like the Pentium III, all Celeron CPUs are multiplier locked. So far nobody has found a way of changing it.

Thanks to its great overclocking abilities, the Celeron 300A used to be one of the most popular types. Something similar is might happen to the new Celeron 533A and 566, as both CPUs should be able to reach 100 MHz FSB absolutely stable, resulting in 800 or 850 MHz core clock. Merely the processor voltage will have to be increased from 1,65 to 1,7 or 1,75V. You may also try 1.8 Volts, but always keep an eye on the CPU temperature.

Celeron’s with Mendocino core can run up to 600 MHz at 2.2 Volts. We tried six different CPUs, but even at 2.3 or 2.4 V there was no way of getting those processors to run faster. One of those processors was an excellent example to show that there is no guarantee for overclocking success. One of our Celeron 400 samples did not even want to run stable at 500 MHz (83 MHz system speed). At the same time a Celeron 433 ran reliably at 600 MHz core speed (92 MHz FSB).

We have to face it. Some Celerons just cannot reach really high clock speeds. I hope you can live with the fact that you have to be a little bit lucky, as there is no way to distinguish a good overclocking processor from a bad one unless you try it out. Some processors can be speeded up extremely well; others will fail at 15% more clock speed.

Upgrading older systems with a Celeron

The first Pentium II CPUs (Slot-1, Klamath core) required 2.8 V core voltage. Nevertheless, most motherboards from this period should be able to provide down to 2.0V as well, because Intel introduced the specifications for their second generation Pentium II (Deschutes, 333+ MHz) quite early. Old 440LX or VIA Apollo Pro boards are certainly no valid platforms for the later Pentium II or today’s Pentium III processors, as those models require 100 or 133 MHz front side bus clock. However, most of those boards are able to work with a Celeron.

For upgraders, the locked multiplier of the Celeron is a benefit, as the CPU will work at its designated clock speed regardless if the motherboard would let you adjust the multiplier or not. Just make sure that there is an updated BIOS version available, as the CPU needs to be supported and the latest micro code update should be supplied by the BIOS of the motherboard. If that is not the case, the BIOS will either report something rather irregular (e.g. 486 at 500 MHz), or the system won’t work at all.

Ideally, the Mendocino Celeron is best suitable for upgrades, while only few of the older motherboards can supply the required 1.5 — 1.65V for the new Celerons with Coppermine-128 core. In other words, go for a Celeron between 400 and 533 MHz unless your motherboard supports the lower core voltages of the new Celeron processors. Celerons at less than 400 MHz are almost impossible to come by. Be careful with the 533, as the new Celeron with Coppermine-128 core (1.5 V core voltage!) is also available at this clock speed (Celeron 533A). You can recognize it by its green color:

The Celeron on the left uses the Mendocino core, on the right is a Celeron with Coppermine-128 core. Running at 2.0V, the Mendocino should work in almost every motherboard, thus it is perfectly suited for upgrades. Don’t forget the benefit of a Socket370-to-Slot1 adapter board in order to run the Socket 370 CPU in a Slot-1 motherboard.

Here you can see a typical Socket370-to-Slot1 adapter board. Don’t forget the CPU cooler/fan, as you cannot keep using Slot-1 components. Together, those two parts should cost between $25 and $35.

Which motherboards support the new Celeron?

I already mentioned it in the first part (Celeron Performance Guide): It’s very important to have a BIOS which supports the Coppermine-128 Celeron and you will need a motherboard which is capable of supplying 1. 5-1.65V core voltage. Actual models (one year or younger) should be able to do this, but the older your board is, the smaller is the probability that it will do it. If you are not sure, please check the website of your motherboard maker.

It doesn’t matter if you have a Slot-1 or a Socket 370 motherboard. As already mentioned, you will require an adapter board for Slot-1 motherboards. Usually, those adapters feature some jumpers, which let you change the CPU’s voltage requirement.

If your board supports 75 or 83 MHz system clock speeds, you get some overclocking options this way. Please note that most adapter boards just have the voltage definition jumpers, but no voltage regulation unit! That means that you will not get more voltage options than your motherboard’s voltage regulator supports.

Some older motherboards support down to 1.8 Volts core voltage and a few freaks are already running their Coppermine processors at this voltage. Generally this high voltage is not a problem, but the core will heat up much more. If you really want to use your processor like this in the long term, make sure you get the best CPU cooling solution you can get. Otherwise, you will certainly reduce the processor’s life span.

Overclocking Guide: That’s how it works

Today, overclocking is no secret any more, it has almost become some kind of sport. The definition for overclocking is simple: Overclocking means operating an IC beyond its specified clock speed. No more, no less.

The core speed is the multiplication of the front side bus clock and the multiplier. Most modern processors work at 100 or MHz FSB clock or more, but the Celeron was kept at 66 MHz FSB clock.

Few years ago, you could overclock processors by choosing a higher multiplier. This option was supposedly eliminated in order to fight CPU remarking. Counterfeit processors have regularly appeared in the market (e. g. a Pentium II 266 which was given a new cartridge, labeled at Pentium II 300), as the CPU speed was only defined by your setting. Nowadays, the restriction to only one multiplier is both some kind of overclocking prevention and counterfeit protection.

As you can see, the only way of overclocking today is choosing a higher front side bus clock. Intel specified 66, 100 and 133 MHz, but today’s motherboards offer some steps in between those large increments. 75 and 83 MHz are very widespread today. Celeron overclocking requires many small increments between 83 and 100 MHz, as most Celerons run perfectly at 83, but fail at 100 MHz FSB. We benchmarked at 92 MHz as well, as this clock speeds closes the logical gap between 83 and 100 MHz.

In case your board should offer 1 MHz-increments (Abit BE6-II, BF6, BX133-RAID, Epox BX7+ and others), you have the chance to find out the maximum clock speed by slowly closing in on the final limit MHz for MHz. Of course this cannot be done in an hour, but you will have to spend one or two days just playing with different clock speed settings. In the end you should have your Celeron running at the highest possible core speed.

Using higher voltages

Today, almost each processor can be run faster than the speed it was labeled for. This applies even more if you raise the core voltage a little bit. One problem is of course the increasing chip temperature, so cooling is very, very important. You should always raise the voltage step by step and never go higher than 15% beyond specs. This way it’s quite easy to get a faster system without risking the processor.

2.1 or 2.2 V have proved to be reliable for Mendocino CPUs. More can sometimes bring the desired success, but the risk for your CPU increases heavily. To have a Celeron 566 running at 850 MHz, you only have to raise the default voltage of 1.65V to 1.75V. Our Celeron 600 did not want to run stable at 900 MHz, so I recommend keeping below this clock speed. You can try at 1.8 or 1.9V, but the temperature at almost 1 GHz can only be fought successfully by a high end cooling solution (e.g. Kryotech devices)

What Do I need to overclock the Celeron?

• Big cooler with a powerful fan
• A motherboard which provides as many system speed settings as possible (particularly between 66 and 100 MHz)
• A motherboard which lets you alter the core voltage

Overclocking speed

The following table includes all Celerons, clock speeds and useful voltage settings.

CPU	Overclockable to	Core voltage
Celeron 300A	100 MHz x4. 5 (450 MHz) 92 MHz x4.5 (414 MHz)	2,1V 2,0V
Celeron 333	100 MHz x5 (500 MHz) * 92 MHz x5 (460 MHz) 83 MHz x5 (416 MHz)	2,1V/2,2V 2,0V/2,1V 2,0V
Celeron 366	92 MHz x5.5 (506 MHz) * 83 MHz x5.5 (458 MHz)	2,2V/2,1V 2,1V
Celeron 400	92 MHz x6 (552 MHz) * 83 MHz x6 (500 MHz)	2,2V/2,1V 2,1V/2,0V
Celeron 433	92 MHz x6. 5 (598 MHz) * 83 MHz x6.5 (542 MHz) 75 MHz x6.5 (487 MHz)	2,3V/2,2V 2,2V/2,1V 2,1V/2,0V
Celeron 466	83 MHz x7 (583 MHz) * 75 MHz x7 (525 MHz)	2,2V 2,0V
Celeron 500	83 MHz x7.5 (625 MHz) ** 75 MHz x7.5 (563 MHz)	2,3V 2,2V/2,1V
Celeron 533	75 MHz x8 (600 MHz)	2,3V/2,2V
Celeron 533A	105 MHz x8 (840 MHz) * 100 MHz x8 (800 MHz)	1,7V 1,65V
Celeron 566	100 MHz x8. 5 (850 MHz)	1,7V/1,65V
Celeron 600	100 MHz x9 (900 MHz) * 92 MHz x9 (828 MHz)	1,75V/1,7V 1,7V/1,65V
Celeron 633	100 MHz x9.5 (950 MHz) * 92 MHz x9.5 (874 MHz)	1,8V/1,75V 1,75V
Celeron 667	100 MHz x10 (1 GHz) * 92 MHz x10 (920 MHz) * 83 MHz x10 (830 MHz)	1,8V/1,75V 1,8V/1,75V 1,75V/1,7V
Celeron 700	92 MHz x10. 5 (966 MHz) * 83 MHz x10.5 (875 MHz)	1,8V/1,75V 1,8V/1,75V/1,7V

* this setting may fail sometimes
** this setting will most likely fail

Test configuration

Test System
CPU	Intel Celeron, Intel Pentium III
Motherboard	Asus CUBX, Intel 440BX chipset Asus CUWE-RM, Intel 810 chipset
RAM	128 MB PC133 SDRAM, 7ns (Wichmann Workx or Memory Solution) CL2
Hard Drive	Seagate Barracuda ATA ST320430A 20 GBytes, 7200 rpm
Graphics card	Asus V6600, nVIDIA GeForce 256 32 MByte SDRAM nVIDIA Drivers 5. 08 for Windows 98 Intel 810 Integrated Graphics Driver Version 4.1
OS	Windows 98 SE 4.10.2222 A
Benchmarks and Setup
Office Applications Benchmark	BAPCo SYSmark2000
OpenGL Game Benchmark	Quake III Arena Retail Version command line = +set cd_nocd 1 +set s_initsound 0 Graphics detail set to ‘Normal’, 640x480x16 Benchmark using ‘Q3DEMO1’
Direct3D Game Benchmark	Expendable Downloadable Demo Version command line = -timedemo 640x480x16
Screen Resolution	1024x768x85, 16 Bit
DirectX Version	7. 0

BAPCo SYSmark 2000 — Windows 98 SE

This chart lines up all results I got during my many days of testing. In brackets you will find the basic Celeron model (multiplier-locked of course) and the clock settings we used. At the bottom are some settings, which did not work stably.

It was interesting to see that a Celeron 366, overclocked to 458 MHz (83 instead of 66 MHz system speed), is faster than a regular Celeron 500. Even more impressive is the Celeron 566, which ran reliably at 850 MHz (at 1.75V). That will give you the same performance as using a Pentium III 667 or 700 — at about half the price!

Direct 3D Benchmark — Expendable Timedemo

Expendable can benefit even more from overclocking. Our Celeron 366 at 458 MHz scores the same result than a brand new Celeron 600! A Celeron 433 at 92 MHz FSB and 600 MHz core speed is able to catch the Pentium III 500E. Again, the 566 at 850 MHz is as fast as a Pentium III 700.

OpenGL-Benchmark — Quake III Arena

Quake III benefits the same way.

Price/Performance Ratio

This chart gives you the actual price/performance ratio of Celeron and Pentium III CPUs. The green lines show the ratio using the regular clock speed, 66 MHz with the Celeron and 100 or 133 MHz with the Pentium III. Of course you get a greatly increased price/performance ratio after raising the FSB clock.

It’s important to know that Intel makes their chip prices according to the core clock speed. That’s why a Pentium III 600E (100 MHz) costs the same as the Pentium III 600EB (133 MHz). However, the 600/133 is as fast as a 700/100 or 750/100, depending on the application. I think this shows once again that running a Pentium III at only 100 MHz system speed is a huge waste of performance. Motherboards and RAM for 133 MHz are no more expensive than 100 MHz components; therefore it’s advisable for Pentium III buyers to choose a 133 MHz system today.

The story is different for users with a small budget. In this case, just the result counts. I think it’s not exaggerated to say that from the price point of view, there is little alternative to an overlocked Celeron with Coppermine-128 core right now. In addition, you can easily upgrade to a Pentium III later.

Again you can see some results missing because those setups did not want to run reliably. I already mentioned that we couldn’t get our Celeron 400 to run at 500 MHz or more. Please be aware that this is an unusually negative result, as most Celeron 400 CPUs should easily reach between 500 and 550 MHz, unless the CPU is already older than approx. 18 months.

The below results were achieved by dividing the Quake III frame rate score by the average price spotted at pricewatch. com.

Conclusion

The Celeron is inexpensive and a decent performer. Particularly the new models (533A to 600 MHz and more) are an excellent choice for performance freaks on a small budget, as they are around only $100-120 and just perfect for overclocking. All new Celeron CPUs (green FC-PGA package) should reach at least 800 MHz, as they do not differ from the Pentium III at all.

We know that the latest Celerons are Pentium III processors, which did not pass the L2 cache test. In order to reduce the number of defective Pentium III CPUs, Intel disables half of the L2 cache (the part where the error is situated), reduces the cache associativity from 8-way to 4-way, restricts them to 66 MHz at higher multipliers and labels those chips as Celeron.

If you are looking for a way to upgrade your Pentium II system, have an eye at the Mendocino Celeron. Older motherboards should easily be able to host this processor as long as you still get an updated BIOS. Celeron models at 500 and 533 MHz can be obtained for less than $100 today and will significantly speed up an old Pentium II 233-333 system.

All Celerons coming in the green FC-PGA package are equipped with the Coppermine-128 core (533 MHz or faster). I don’t recommend buying such a CPU without checking twice if your motherboard is able to provide 1.5 -1.65V. You are in good shape if your board can host one of the new Celerons, but even if the voltage requirements are not met, you can still take advantage of a Celeron 400-533 with Mendocino core.