Introduction
The Pentium Pro is around now for several years and still it never made it to a best seller as its siblings Pentium, Pentium w/MMX and Pentium II. The main reason for that is and was its weakness with 16 bit code, such as Windows 3.x or Windows 95. The Pentium Pro used to be a clear winner under Windows NT though and there are still a few advantages over the Pentium II in case you want to use it in a high end environment.
The Pentium II’s advantages over the Pentium Pro are the additional L1 cache, segment cache registers and MMX extensions. Except of the larger L1 cache the other two features are not improving the Pentium II in high end server environments, but make it more attractive when used under 2nd class operating systems such as Windows 95. The advantage of the Pentium Pro however is the 8 fold larger cacheable area of 4 GB instead of the mediocre 512 MB of the Pentium II, the ability to run in up to quad CPU configurations (PII only dual) as well as its faster L2 cache. You can also get Pentium Pro CPUs with a larger L2 cache than Pentium II CPUs, as long as you pay big bucks for the 1 MB version of the PPro.
Intel’s road map has a good reason why it’s still placing the Pentium Pro in the high end sector for servers until the Deschutes for Slot 2 is available, because the high end servers want quad CPUs and are not afraid of 4 GB of memory. However it’ll be quite a while until Deschutes/Slot2 will be out, before that we’ll get Deschutes/Slot1. I’d actually like to take the opportunity and stress again that Slot 2 WILL NOT be the successor of Slot 1, although 99.9% of the second to fourth rate computer websites and magazines seem to tell you that. This includes some big websites as well as some big magazines. The Slot 2 Deschutes will COEXIST to Slot 1, ‘Deschutes’ stands for nothing else than a Pentium II core that is shrunk to quarter micron size and that runs faster than 300 MHz. The upcoming Pentium II 333/66 will be a ‘Deschutes’ just as well as the later next year evolving Slot 2 CPU at 400/100 MHz (Intel hasn’t picked a name yet). I hope that all the wonnabe computer journalists have got the message now.
Until the Slot 2 CPU will come out, high end servers are either based on really cool CPUs without the Intel logo or a Pentium Pro is working in them. Slot 2 will later next year offer up to 8 CPU configurations, cacheable area up to 4 GB, the L2 cache will be running at CPU core speed and the CPU will run at 100 MHz ‘front bus’.
Today you can’t equip a Pentium II server with more than 512 MB RAM without a horrible performance loss, since its cacheable area is only 512 MB and if you run it with more you got to disable both caches, L1 as well as L2!!! This results in a perfomance at Pentium 75 niveau. For any high end system requiring over 512 MB of main memory, you still have to chose a Pentium Pro system or wait till next summer. But please be aware of problems with new system architectures. The Pentium II only now has the 440LX chipset to show its performance reserves in combination with SDRAMs, Ultra DMA and AGP, and the first Pentium generation (socket 4, 60/66 MHz, 5 Volts) had to wait for the Neptune Chipset and socket 7 and later for the 430HX to visibly show its much higher performance compared with 486 DX4 CPUs (up to 133 MHz). Furthermore the first generation of new hardware has often been afflicted by bugs or poor performance especially when coming from Intel. Finally the higher price of brand new products quenches many users from buying in the first best moment. So if you need to choose a fast server CPU, don’t just negate the Pentium Pro without considering its advantages; today the versions up to 180 MHz can sometimes be obtained quite cheap.
The Pentium Pro itself
- 150, 166, 180 and 200 MHz
- overclockable up to 233 MHz without active cooling
- 60/66 MHz bus clock
- integrated L2 Cache of 256 KB, 512 KB or 1 MB. The 256 KB type will be out of production soon.
- Superscalar 32 Bit ‘specialist’ (decoupled, 12-stage), not suited for 16 Bit software under Windows 95
- 0.35 micron
For detailed information just take a closer look at Intel’s Pentium Pro Processor Data Sheet.
The memory question:
Please think about the amount of main memory first. Many boards cannot be arbitary equipped with SIM modules. The most frequent restriction is the total amount of memory ICs; all chips have to be adressed correctly by the chipset to ensure a fully operational system (problems start with a wrong detection of the total memory size and end with hangups that you usually don’t refer to the memory since the SIMMs tried individually don’t cause such problems). In case you want modules each of 64 MB or more, please consider chosing those with integrated drivers chips for memory mapping/adressing, they successfully avoid problems with larger IC-placements on the modules. The 440FX supports BEDO (burst extended data out) DRAM as well. This type of memory should be some per cents faster, but much more expensive and nearly impossible to get, so better forget about it. A more reasonable investment are 36 Bit modules (with parity). Each Byte has its corresponding parity Bit for ECC (error correcting code) to correct 1 Bit memory errors and to detect 2 Bit errors.
The Boards:
Quite important is absolute stability and I’m happy to say that there were no difficulties during the tests except three boards always timing out while performing the Highend Winstone; but I don’t want to accuse the boards, since I did not find any high end application which would run with errors or anyhow unstable on these candidates. I think this cosmetic bug is caused by some item of the Winstone sequence or by some aspect of my configuration that either Winstone or the motherboard does not tolerate. I gave up thinking about it after I tried large parts of Microsoft’s product family and SDKs as well as 3D Studio Max, Lightwave 3D, Borland C++ and Delphi.
All boards are based on Intel’s ‘Natoma’ 82440FX PCI chipset and PIIX3 supporting FPM or EDO DRAM, parity or ECC check and other known goodies: Dual PIO Mode 4 EIDE controllers, floppy controller, 2 serial ports (with 16550), 1 parallel port (ECP/EPP) and as a matter of principle an USB port as well.
Overclocking:
As almost all Intel CPUs, the Pentium Pro is pretty easy to overclock. I have not heard of any multiplier restrictions so far, so you may still be lucky running 150 MHz models at 166 or even 180 MHz, 166 MHz at up to 200 MHz and 200 MHz versions at 233 MHz. If you should use some power cooling as offered by Kryotech, you may well be able to go up to 300 MHz. Higher bus clocks are hardly worth the try, because the Pentium Pro’s performance is mainly determined by the L2 cache speed. This speed is not changed when switching to a different bus clock.
Abit AB-PS6
As many other ABit motherboards too, the PS6 features Soft Menu to select the CPU clock in the system BIOS. Furthermore ABit successfully supports 75 MHz bus speed for the Pentium Pro, what allows you to overclock the CPU to 225 MHz (75 MHz x 3). The board needs a VRM module for supplying the CPU with the correct voltage. There is nothing to complain, except the positioning of the IDE connectors: They are in front of the three upper PCI slots, so you may get into trouble in case you have more than one full size PCI card (like frame grabbers). Anyway, this board is not explicitly meant for server systems; with just two memory banks (4 SIMMs) it’s difficult (or very expensive) to exceed 256 MB of memory without obtaining 128 MB memory modules, what certainly won’t be too cheap…
ABit AB-PS6, Rev. 1.21
ATX format, ATX power supply, Intel 440FX chipset; 3x ISA, 4x PCI; 4x SIMM; Award flash BIOS; cache on CPU card (socket 7) or on CPU (P6); external frequencies: 60, 66 MHz; multipliers: up to x3.5; I/O chip: Winbond; PIO 4 onboard; FDC onboard; 2x serial 16550; 1x EPP/ECP parallel; 1x PS/2 mouse; USB onboard (without connector); IrDA support (without connector); SDMS support.
Asus P65UP5 w/ C/P6ND
You can find the same baseboard in the Socket 7 Review, there in combination with the CPU card P55T2D (430HX). Here we have the Pentium Pro pendant. This board is designed for excellent flexibility, 8 SIMM sockets and 5 PCI slots confirm this. Its very idiosyncratic design can cause mechanical difficulties: Not any case has enough free space for the CPU card! You will have to disclaim your harddisk and floppy bay or to look for a lavish case. Not only the card’s extents represent an obstacle but also the fact that the air circulation must be provided to ensure a long life for your CPU(s). If you want to change the Pentium Pro card to the Pentium card, don’t forget to upgrade to the correct BIOS version; otherwise your system won’t even boot up correctly.
P65UP5 baseboard, Rev. 1.2
Baby AT format, AT power supply, chipset on CPU card; 3x ISA, 5x PCI, 1x Asus Media Bus extension; 8x SIMM; Award flash BIOS; cache on CPU card (socket 7) or on CPU (P6); external frequencies: 60, 66 MHz; I/O chip: Winbond; PIO 4 onboard; FDC onboard; 2x serial 16550; 1x EPP/ECP parallel; 1x PS/2 mouse (without connector); 1x USB (without connector); IrDA support; SDMS support ver. 3.07.
P6ND CPU Card, Rev. 1.1
Dual processor socket 8 CPU card; Intel 440FX chipset; external frequencies: 60, 66 MHz; multipliers: up to x4.0.
MSI MS6107
This Dual Pentium Pro motherboard does not need voltage regulator modules (VRMs) and fulfils higher demands on a server motherboard: 5 PCI slots as well as three memory banks should be enough to ensure proper upgrading of hardware or memory. The floppy/IDE connectors are not placed optimally, since you will have to give up one or two full size PCI slots. But then I think it’s rather scarce that somebody has more than three ironing-board-size PCI cards. As you can see on the picture, MSI uses AMI BIOS.
MSI MS6107, Rev. 1.0
ATX format, ATX power supply, Intel 440FX chipset; 3x ISA, 5x PCI; 6x SIMM; AMI flash BIOS; external frequencies: 60, 66 MHz; multipliers: up to x3.5; I/O chip: Winbond; PIO 4 onboard; FDC onboard; 2x serial 16550; 1x EPP/ECP parallel; 1x PS/2 mouse; 2x USB (without connector); IrDA support (without connector).
Shuttle HOT-613
Equipped with one CPU, Shuttle’s Dual Pentium Pro ATX Board seems not to be the fastest, but as mentioned above, I wouldn’t care too much about this. Quality is quite good, but I’m substantially missing additional memory banks. The four sockets are just not enough to provide an adequate expandability. Four PCI and three ISA slots can be considered as minimum as well. When equipping a second processor you will have to get the VRM module that is merely integrated for the first CPU, this reduces the costs and can be recommended for systems that possibly some day will need a second CPU. BEDO DRAM is also supported despite you will hardly be successful to get some in case you want to use them. With this particular board, the position of the IDE connectors can be apologized, because the second CPU socket takes all space left on the upper part of the board. Good to see that clock multipliers are supported up to x4.0 what makes the use of future overdrive processors up to 266 MHz possible.
Shuttle HOT-613, Rev. 2.0
ATX format, ATX power supply, Intel 440FX chipset; 3x ISA, 4x PCI; 4x SIMM; Award flash BIOS; external frequencies: 60, 66 MHz; multipliers: up to x4.0; I/O chip: ITE; PIO 4 onboard; FDC onboard; 2x serial 16550; 1x EPP/ECP parallel; 1x PS/2 mouse; 2x USB (without connector); IrDA support (without connector).
Tyan S1662D
Here we have the quintessence of a server motherboard. 8 SIMM sockets and 5 PCI slots should be enough for most demands. This board needs VRM modules to be plugged in, since there is not much space left for them onboard. Such a board is usually not chosen due to performance considerations; there are faster boards among the candidates. Overdrive processors up to 266 MHz can be used, the multipliers needed for this clock speed are supported.
Tyan S1662D, Rev. ?
Baby AT format, AT power supply; 3x ISA, 5x PCI; 8x SIMM; Award flash BIOS; external frequencies: 60, 66 MHz; multipliers: up to x4.0; I/O chip: SMC; PIO 4 onboard; FDC onboard; 2x serial 16550; 1x EPP/ECP parallel; 1x PS/2 mouse (without connector); 1x USB (without connector); IrDA support; SDMS support ver. 3.07.
Tyan S1668
Here we have an ATX version of Tyan’s proposal of a Dual Pentium Pro motherboard. Gladly Tyan decided to equip this board with 8 SIMM sockets, 5 PCI and 3 ISA slots slots; more would only be a case for the 450GX or KX chipset in conjunction with more than two CPUs. Performance is not an issue, but I think it’s worth mentioning that this board is the fastest of the seven boards I got. Very good: The EIDE and floppy connectors are not placed straight together, so that all 5 PCI slots should be able to take extra long PCI cards. Again, BEDO DRAM is supported as well as the ‘set books’ ECC/parity. Thanks to the ATX design, the power supply fan provides some coolness; the two CPU and VRM sockets are pretty close together, otherwise it would become a hot affair. And as you certainly already know: The really good things are never cheap. Nevertheless, I think this is a very fine motherboard; I just would desire a PS/2 mouse and USB connector for total happiness.
Tyan S1668, Rev. ?
ATX format, ATX power supply, Intel 440FX chipset; 3x ISA, 5x PCI; 8x SIMM; Award flash BIOS; external frequencies: 60, 66 MHz; multipliers: up to x4.0; I/O chip: SMC; PIO 4 onboard; FDC onboard; 2x serial 16550; 1x EPP/ECP parallel; 1x PS/2 mouse; 1x USB (without connector); IrDA support (without connector).
Tyan S1672 “Tacoma”
Last but not least the S1672 is a single Pentium Pro motherboard which fulfils all expectations a customer could have: 4 PCI / 4 ISA slots, 6 memory sockets, no obstacles for full-size PCI cards, additional AT power connector and all other usual gimmicks. Good quality and good performance are important items, flexibility is Tyan-like as with the two other boards as well. Again, BEDO DRAMs are supported and also clock speeds up to 266 MHz. Once again I’m missing the USB connectors and the VRM module, that has been integrated into the motherboard itself.
Tyan S1672, Rev. ?
ATX format, ATX & AT power supply, Intel 440FX chipset; 4x ISA, 4x PCI; 6x SIMM; Award flash BIOS; external frequencies: 60, 66 MHz; multipliers: up to x4.0; I/O chip: SMC; PIO 4 onboard; FDC onboard; 2x serial 16550; 1x EPP/ECP parallel; 1x PS/2 mouse; 1x USB (without connector); IrDA support (without connector).
Benchmarks Windows NT 4.0
Testing environment:
CPU: Pentium Pro at 200 MHz (66 MHz x 3)
OS: Windows NT 4.0
Main memory: 64 MB EDO (4x 16 MB, Micron, 50 ns, 8-chip)
Harddisk: Quantum Fireball ST 3.2, DMA mode 2
Graphics card: Matrox Millennium 4 MB
Benchmark: Business Winstone 97
If you already read the Socket 7 Review you may have noticed that the test configuration is the same. Thanks to this it’s possible to compare the business performance with an arbitary socket 7 CPU. It was not necessary to equip the system with more than 64 MB, because business applications won’t run much faster. You need memory intensive applications to benefit from a larger main memory size.
Logically, the Highend Winstone would be more suited for the Pentium Pro, but the results differ just by 0.9 points so that I wanted to give up making charts to show differences that are not worth talking about them, nevertheless here they are. The reason is of course that such applications need very much CPU performance; since the L2 cache is a constituent part of the CPU, the board manufacturer has left only a few aspects to optimize system performance.Benchmark Results:
It’s very becalming to see that all boards can be recommended in some aspect. Sure, the MSI MS-6107 and the Tyan S1668D can be called winners, but I think the differences at very high performance requirements can be neglected. The Pentium Pro CPU contributes more performance than any other x86 CPU at the same clock speed and buying a Pentium Pro for business applications is not very suggestive. The Pentium II 233 is cheaper and has similar performance for business or multimedia applications – combined with SDRAMs maybe even better.