Take Two
If you take a look at the CPU market of the last months, you will realize that Intel has been releasing one Celeron version after the other. The Celeron at 466 MHz is the fastest version right now, most likely marking the end of the line for the Celerons at 66 MHz FSB. The next new Celeron at 500 MHz will be running at 100 MHz FSB, but this won’t happen before Intel has released the successor of the BX-chipset, called ‘Camino’ and new Pentium III processors that run at 133 MHz FSB. Tom had the Celeron run at 618 MHz, which shows that this CPU is technically able to run at clock speeds way beyond 500 MHz. As you know, in many applications the Pentium II is a bit faster than a Celeron at same clock speed, due to the slower front side bus. Of course this is a disadvantage, but if you compare the price for a 466 MHz Celeron and a Pentium II 450 with memory and motherboard, you might understand what I mean.
Celeron beats Pentium II
Except of the common benefits of a Celeron (low price, high performance) it comes with some other `goodies` on which you should take a look at. As you know, due to the multiplier lock of Celeron, overclocking is only possible by rising the bus speed. 66 MHz of course is not particularly standard any more, but as Intel wants to sell Pentium II CPUs as well, it will take some more time until we will get 100 MHz-Celerons. I suppose they will be available as soon as the Pentium III CPUs go 133 MHz.
As long as the Celeron is restricted to 66 MHz bus, the only thing you can do is either try to get one of the last 300 MHz Celerons, or run it at 75 or even 83 MHz bus speed. The 300 MHz type is the best one for overclocking, because you can simply change the FSB from 66 to 100 MHz and almost each of those CPUs runs at 450 MHz core speed. The 333 MHz model would have to bear 500 MHz, the 366 MHz type even 550 MHz, which won’t run reliably without exotic cooling.
The 2nd best choice for overclocking are the Celeron models running at 366, 400 or 433 MHz. By rising the bus speed to 75 or 83 MHz you usually don’t risk any components and still get higher CPU performance. So the Celeron 366 will run at 412 MHz, the 400 MHz type runs at 450 MHz and the Celeron 433 should reach 487 MHz. I intentionally wrote ,should` because this is already a clock speed which the CPU possibly may not tolerate.
Slot-1 or Socket 370?
There are some reasons why I prefer the Socket version of the Celeron: First, both the CPU and the motherboard are clearly cheaper than the slot versions. I also cannot support the argument that Socket 370 could be a one way path. One the one hand the Slot1 Celeron will soon go away, as already seen with Celeron 466, which is only available as PPGA-version. On the other one you can still use a PPGA-Celeron on a Slot-1 motherboard, all you need is an adapter card from one of the various motherboard makers. Those CPU converter boards have some other advantages, which you could find useful.
At the moment there are around 20 converter boards available, most from the known motherboard manufacturers. They all work fine basically, but some may have problems at 100 MHz bus speed. There is a few of them, which are better than the others:
The Asus S370
Rev. 1.02 — currently the smartest solution of a Socket 370 to Slot1-Converter
This card enables the PPGA-Celeron to run as dual-processor by default. It also enables you to adjust the CPU core-voltage between 1.8 — 2.6 V via 5 jumpers.
The MSI MS6905 Rev. 1.1
The MS6905 Rev. 1.1 does not have the voltage jumpers of the Asus S370, but it also enables dual-mode for Celerons by default.
Soltek’s SL-02A Rev. A2 and Elitegroup’s Smart Adapter Rev. 1.1 are also supposed to enable dual-mode by default, but we have not tested them.
Why using two CPUs?
Many people still think that using two CPUs in a dual motherboard doubles the performance. But don’t be disappointed if you won’t notice any obvious performance gain. The magic word is ‘multitasking’ and requires Windows NT. Didn`t you ever try to open an application like Corel Draw while your computer was zipping some files or was playing a DVD or CDI movie? Two performance-hungry tasks are usually enough to slow down your system considerably.
Here’s a way of benefiting from two CPUs: The system shares the load to both processors and makes the applications really run parallel. So it’s no problem to work on a Corel Draw project while rendering an overkill scene in 3D Studio Max. You can even write a CD while processing large images with Photoshop.
The second way of benefiting from a dual processor system is using multi-threaded applications, which have been optimized for multiprocessor environments. 3D Studio Max is one of the best examples, using two CPUs reduces the rendering time by almost 50%.
The Dual Celeron System
Since the Celeron ‘Mendocino’-core is nothing more than a Deschutes with integrated 128KB L2 Cache, of course it also features the dual processor capabilities. Removing them would have required some redesigning of the CPU core, which would have cost just too much money. Intel went the easier way and simply cut the required contact to the chipset. Now all we have to do is restoring this link which you can do best by getting the Asus or MSI converter board. I used the following environment for the tests:
- Motherboards: Maxtium BXAD, Tyan S1836 and MSI MS6120.
- Memory: Siemens 128MB PC-100 SDRAM with ECC
- Video:Hercules Dynamite TNT with nVIDIA Drivers 0.48
- CPUs:2 Pentium II 400 or 2 Celeron 400 CPUs
- Harddisks:Adaptec 2940UW Controller with 2 IBM DVGS 9 GB harddisks
- OS:Windows NT 4.0 Server, Service Pack 4.
The basic benchmark was Highend Winstone 99. To show the power of a dual CPU system I had it run twice with other tasks running:
- Single Highend Winstone 99
- Highend Winstone 99 + 800MB WinZIP files compression
- Highend Winstone 99 + 800MB WinZIP files compression + CDI/MPEG video playback with Xing MPEG Player 3.3
To make the CPU load as high as possible, Winstone ran from harddisk 1, WinZIP on the 2nd harddisk and the CDI video from an IDE CD-ROM. - Last but not least I had 3D Studio Max R2 rendering flaresun.max.
Benchmarks and Evaluation Part I
I ran all CPU configurations in all three dual boards: Maxtium BXAD, Tyan S1836 and MSI MS6120; the benchmarks were performed with the MSI board. Since a dual CPU system is pretty useless in Windows 95/98, I excluded the Business Winstone benchmark.
The first and obligatory benchmark is the Highend Winstone 99 under Windows NT.
As you can see the Pentium II 400 easily outperforms all ,regular` Celerons up to 433 MHz including even the Celeron 400/100 as well. As a matter of fact the gap is really small; I even had the benchmark run six times each to determine the exact performance difference and took the highest value I got.
To create more work for the CPUs, I had WinZIP compress 800MB of different files while Winstone was running; most of them Windows 98 and some .wav files. Winstone ran from a second partition on the first DGVS hard drive while WinZIP was operating on the second disk drive. The result was quite a surprise: The Celeron is slightly faster than a Pentium II at same internal and external clock speed, which can only be explained by the fact that Celeron’s smaller L2-cache is running at double the speed of Pentium II’s L2-cache.
Benchmarks and Evaluation Part II
To see what will happen if three heavy tasks are running, I repeated the last test and added the playback of the Star Trek IV movie (CDI/MPEG using Xing MPEG Player 3.3) from an IDE CD-ROM. Here the Pentium II CPU is clear in front, as I would have expected it. The bigger the amount of data, the greater is the impact of a larger L2 cache, even if it only runs at half CPU clock speed as with the Pentium II.
Here you can see the render time (in seconds) for the 3DSMax sample flaresun.max, this means the shorter the better. You can see that pure CPU performance has the biggest impact; the bus speed has fewer impact than with memory intensive apps like those of the Highend Winstone.
Pentium II or Celeron?
This is a question, which is very easy to answer, the only reason to buy a Pentium II for a dual processor system is its higher bus clock. But in my eyes the difference is too small to spend almost the double for approx. 5-10% more performance, which you will hardly notice. For the price of two Pentium II 400 CPUs you can get two Celeron 433 PPGA CPUs with converter boards and you will still have money left for at least some extra memory. Even the cacheable area of the Celerons (300A or faster) is 4 GB as well.
High end dual processing was never as cheap as now with the Celeron. You can take most CPU converter boards and modify them or go for the new Asus or MSI types in the first place. If you want to run 100 MHz right now, you should stick with the Asus S370, which enables you to increase the CPU’s core-voltage, thus making it perfect for overclocking. I’ve not experienced any problem so far at 100 MHz FSB, but it’s never wrong to be careful! Of course you should take a closer look at the motherboard’s BIOS; make sure that is not older than 3-4 months and supports the Celeron CPU family, including the right micro code!!!
If an upgrade should become necessary, you can still get either a faster Celeron, a Pentium II or Pentium III CPU. The only thing you have to consider is getting a 100 MHz capable motherboard (BX chipset) and if possible PC-100 memory at the same time.
