With great difficulty Intel managed to release its notorious i820, which had undergonenumerous reconstructions and which launching had been delayed and postponed several times.This chipset appeared the first one to support Rambus memory technology, which was very promisingand progressive according to Intel. So, this chipset started slowly approaching the mass market.However, the first signs of this awaited process were not so numerous: very few mainboards basedon i820 appeared on the shop shelves. The mainboard manufacturers were not very enthusiasticabout pushing their i820 based products into the market since the cost of the end systemappeared incredibly high taking into account the price of RDRAM modules used. In particular,the average price on RIMM modules is about 10 times higher that that on SDRAM modules of the samecapacity. It is very unlikely that somebody will pay this money for a system, which performanceproves practically the same as that of a system using a much cheaper SDRAM.

So, Intel had to think of a better solution for those who longed for AGP 4x and 133MHz bussupport, which was by that time introduced only in i820 chipset. This solution turned out anadditional MTH controller supporting SDRAM, which the mainboard manufacturers could easilyinstall onto their products. As a result, i820 based mainboards with SDRAM support appearedthe most popular ones and were the first to come into the market. Among those we have to pointout Intel CC820, the first i820 based mainboard really available for purchase. Then come someproducts from other manufacturers, such as Supermicro P3SCD, which we successfully managed toget for testing.

In the current review on Supermicro P3SCD we will try not only to analyse the mainboard featuresbut also to find out the influence of the additional MTH controller on the performance of i820based system. We will do our best to answer a very vital question: does it make any sense tochange to a board made on a more up-to-date Intel chipset?

Specifications

• CPU
  • Supports Slot 1 Intel Pentium III 450-733MHz;
  • Supports Slot 1 Intel Pentium II 350-450MHz;
  • 100/133MHz FSB;
• Chipset
  • Intel 820 (MCH 82820 + MTH 82805AA + ICH 82801AA + FWH 82802AB);
• Memory
  • Two 168-pin DIMM slots 3.3V each;
  • Up to 1GB PC100 SDRAM support;
  • Suspend to RAM;
• Slots
  • 1 universal AGP slot with 4x mode support;
  • 1 AMR slot;
  • 5 32-bit PCI-slots supporting BusMastering;
• I/O
  • 2 UltraDMA/66 channels supporting BusMastering;
  • Integrated AC'97 2.1 audio subsystem;
  • 2 USB-ports;
  • PS/2 mouse and PS/2 keyboard connectors;
  • 2 serial ports and 1 parallel port with ECP and EPP support;
  • 1 FD port for up to 2.88MB devices;
• Other
  • Wake-On-LAN connector;
  • IR connector;
  • Wake on keyboard, mouse, LAN and modem;
  • Hardware monitoring;
  • Case open detector;
• Form-factor
  • ATX, 295x209cm.

The mainboard is supplied in a colorful box with a proud note: "Designed in the USA", however,the manufacturer country is not mentioned anywhere. Besides the mainboard itself, the supplyincludes 1 UltraDMA/66 cable and one floppy drive cable, a detailed illustrated user's manual(one for all i820 based Supermicro mainboards) and a CD disk. The disk content is also hardlysurprising: drivers, hardware monitoring utility, DMI and BIOS reflashing utility.

MTH

Before passing over directly to the mainboard, we would like to particularly dwell on MTHcontroller, which we only briefly mentioned in our i820 Chipset Review.

As is known, at first i820 chipset didn't have any SDRAM interface. Under the pressure ofthe public Intel had to make it possible to use SDRAM on its i820 based mainboards. And althoughthe offered solution was not the optimal one (they simply added 82805AA controller translatingthe requests to RDRAM into the corresponding requests to SDRAM), it was made so rapidly that thefirst mainboards equipped with SDRAM support managed to crop up even before the first ones withRDRAM. However, this hurry as well as Intel's reluctance to make any changes to the chipsetcreated a very paradoxical situation. At first, the data transferred from the CPU through the64bit bus had to be transformed in the chipset for further transfer through 16bit Rambus channeland then in MTH they were converted for the 64bit SDRAM bus. Now i820 memory architecture with MTHhanging somewhere aside looks as follows:

As you can see from the picture above, the appearance of MTH doesn't exclude the presence ofRIMM slots on the mainboard. In other words, i820 based mainboards can be equipped not only withDIMM or only with RIMM slots but also with both of them at the same time. However, in this caseyou should keep in mind that they cannot be used simultaneously.

So, Intel 82805AA Memory Translator Hub (MTH) provides SDRAM support when connected to DirectRambus channel. MTH can be used only together with 82820 MCH and is connected to its Rambuschannel working at 400MHz. Besides, MTH supports only PC100 SDRAM working at 100MHz independentlyfrom the system bus frequency. It means that using faster PC133 SDRAM on i820 based mainboardswill unfortunately make absolutely no sense: it will anyway work at only 100MHz. The second unpleasantthing about MTH is the fact that all timings are configured with the data saved in SPD module,which results into a number of drawbacks. First, it appears impossible to overclock memory bymeans of changing CAS Latency for instance. And second, there occur some problems with the useof memory modules without SPD. Taking into account everything mentioned above and bearing inmind that the data conversion in MTH also requires a certain time, we get a very unattractivepicture of the system memory, which turns out pretty slow. A bit later during the benchmarks wewill see if these pessimistic forecasts come true, and now let's talk about the main peculiaritiesof Supermicro P3SCD.

Closer look

Supermicro P3SCD mainboard made on the newest Intel chipset can boast a set of absolutely newfeatures: AGP 4x and 133MHz system bus support. If you want to learn more about these features,check our i820 Review. AGP 4x allows doubling the theoretical data transfer rate via AGP bus,which however doesn't influence the today's gaming applications performance. As for the FSBfrequency of 133MHz required for some new processors, its support is represented by a new AGPfrequency divider - 2, which is exactly the feature all i440BX boards lack. Together with theCPU voltage regulator intended for 1.3V P3SCD can support all Intel slot processors availablein the market at the moment including the notorious Coppermine.

Despite the coming end of Slot 1, Supermicro P3SCD is equipped with this particular processorslot. And although Intel plans to stop manufacturing Slot 1 processors by April and to fullyshift to Socket 370 ones, Supermicro is still guided by the today's realities. In fact, Slot 1processors are now much more frequent than their Socket 370 fellows, especially since the latestCoppermine models aren't yet made with FC-PGA. And when FC-PGA finally replaces Slot 1 once andfor all, those of you who would like to change the processor they have been using with theSupermicro P3SCD board will be able to do it with the help of corresponding converters(supporting Coppermine). Most leading mainboard manufacturers, such as Iwill and MSI, havealready started announcing numerous converters of the kind, so it shouldn't be a problem atall.

P3SCD on i820 chipset officially supports only 100 and 133MHz system bus frequencies, andhence only the latest Intel Pentium II and Intel Pentium III CPUs. However, it doesn't meanthat you won't be able to use Intel Celeron or 66MHz Pentium II with this board. SupermicroP3SCD allows setting FSB equal to 66MHz (though it isn't mentioned in any manuals and documents)and so, your Celeron will hardly face any problems when working with this board.

As for the memory, the provided 2 DIMM slots made due to MTH 82805AA support PC100 SDRAMmodules of up to 512MB. Of course, 2 DIMM slots on a relatively expensive mainboard for High-EndPCs may turn out not enough, however, you shouldn't blame the manufacturer for that. It is Intelthat doesn't allow making more. By the way, the similar situation occurs with RIMM modules installedonto i820 based mainboards. According to Intel's current instructions it is not permitted to equipi820 based mainboards with more memory slots. And now Intel is working on some new guidelinesofficially allowing mainboard manufacturers to launch their products with 3 RIMM or 2 RIMM and 2DIMM slots simultaneously.

Except the AGP slot and 5 PCI slots (which has become a certain standard today), SupermicroP3SCD is also equipped with an AMR slot for a comparatively cheap software modem. There are noISA slots because they require an additional microchip to be installed into the i820 based board,which tells on the cost of the end product, and besides there shouldn't be any ISA slots at all,according to PC99A specification. As a result Supermicro P3SCD appeared quite compact and will fitinto any ATX-case. The power supply connector is very conveniently located behind the processorslot but at the same time very close to the edge, so the wires going from the power supply unitdo not block the CPU cooling. And in general, Supermicro P3SCD design is very cleverly arranged,the mainboard has a lot of capacitors and all slots allow installing full-size expansion cards.

Besides, like all the mainboards based on 800-chipsets, P3SCD has integrated AC'97 compatiblesound (which can be surely disabled). And although this solution involves the CPU resources duringthe sound playback, the modern processors don't care about it that much and cope with this taskalmost without any losses: the performance drops only by 10-15% at the most. By the by, more andmore mainboard manufacturers start giving up the external ICH soundchip, which is a clear evidenceof the growing popularity of softsound. No doubt that it should become more popular, since the boardappears cheaper and thanks to Intel the problems with the drivers don't trouble us any more.

Now let's pass over to the BIOS. Although AMI BIOS version 1.18 used in Supermicro P3SCD can'tboast fast booting, it offers a wide range of different settings. In particular, Setup allows a veryuseful option: manual IRQ assigning for PCI slots.

Hardware monitoring of the mainboard controls 5 voltages and two temperature sensors - the firstsensor is built into the processor core and the other one is external and is connected to thecorresponding plug. Unfortunately, the external sensor is not included into Supermicro P3SCD package.The mainboard is also provided with 3 fan connectors, which allow checking their rotation speed. Andwe should also mention a very originally looking connector for the external light emitting diode,which signals the CPU overheating.

All in all, Supermicro P3SCD mainboard looks very nice and makes a highly positive impression.It has already turned a very good tradition to mark all the ports with different colors complyingwith PC99 specification. However, both IDE-ports are of the same black color for some reason. Sincei820 chipset is made with 0.25 micron technology it heats much less than its predecessors and hencecan do without the heatsink. And there isn't any, actually.

Overclocking

It seems quite strange to write about CPU overclocking on Supermicro mainboards. The boards ofthis company famous for its server solutions have always followed all Intel specifications and don'tsupport any other frequencies except the standard ones. And instead the Supermicro users got veryhigh-quality, stable and reliable products. However, P3SCD possesses some CPU overclockingopportunities.

First of all, the board has a special jumper for manual resetting of the external frequency.The available values are: AUTO, 100 and 133MHz. AUTO also allows you to get 66MHz with IntelCeleron or old 66MHz Pentium II. Secondly, BIOS Setup of this mainboard supports an even broaderfrequency range: 66, 100, 105, 114, 120, 124, 128, 133, 138, 143, 148, 150, 152, 150 and 160MHz.

On the other hand however, overclocking arouses some serious problems. And again as in manyother cases it is Intel that hatches the mischief. FWH from the i820 chipset is clocked dependingon the PCI bus frequency. But if you set the FSB frequency other than 66, 100 or 133MHz, the PCI busfrequency appears a bit higher than the required one. And since this hub doesn't prove very stableat higher frequencies, 124 and 128MHz FSB appear simply useless: the mainboard doesn't work at all.And as for the opportunity to set the PCI divider manually, Supermicro P3SCD doesn't have any,unfortunately.

So, in general, if you want to overclock your CPU, you'd better do it on the mainboards bysome other manufacturers such as the beloved ABIT, for instance, although it is possible to doit on Supermicro as well.

Performance

Keeping in mind that Supermicro P3SCD is the first i820 based mainboard supporting SDRAM,which we managed to get for testing, we decided to slightly veer away from the usual way ofbenchmarking. Let's pay it a bit more attention this time. And we will regard the obtainedresults as illustrating the way i820 works with SDRAM in general, because they are very closeto what we saw with Intel CC820 mainboard.

So, our system on i820 with SDRAM included also:

• Intel Pentium III 600B CPU (4.5x133)
• Supermicro P3SCD mainboard
• Chaintech Desperado AGP-RI40 graphics card (NVIDIA Riva TNT2, 16MB SDRAM)
• Creative Sound Blaster Live! sound card
• IBM DJNA 372200 HDD
• 128MB PC100 SDRAM by SEC

We compared its performance with that of the following i820 system with RDRAM:

• Intel Pentium III 600B CPU (4.5x133)
• AOpen AX6C-L mainboard
• Chaintech Desperado AGP-RI40 graphics card (NVIDIA Riva TNT2, 16MB SDRAM)
• Creative Sound Blaster Live! sound card
• IBM DJNA 372200 HDD
• 128MB PC800 RDRAM by SEC

with that of i440BX system:

• Intel Pentium III 600 CPU (6x100)
• ABIT BF6 mainboard
• Chaintech Desperado AGP-RI40 graphics card (NVIDIA Riva TNT2, 16MB SDRAM)
• Creative Sound Blaster Live! sound card
• IBM DJNA 372200 HDD
• 128MB PC100 CAS2 SDRAM by SEC

and with that of the system on VIA Apollo Pro 133A:

• Intel Pentium III 600B CPU (4.5x133)
• Chaintech 6ASA4 mainboard
• Chaintech Desperado AGP-RI40 graphics card (NVIDIA Riva TNT2, 16MB SDRAM)
• Creative Sound Blaster Live! sound card
• IBM DJNA 372200 HDD
• 128MB PC133 CAS3 SDRAM by Micron

The resolution was set to 800x600 at 16bit color depth for all 3D applications, all other caseswere mentioned separately.

First we ran wstream, the only application where i820 based system with RDRAM proved anindisputable leader:

This test mainly shows the performance of the memory subsystem working with giant vectors andinvolving about 24MB memory. As you can see, i820 based system with SDRAM appeared dramatically slow.Nothing to be surprised with, actually. If the system uses RDRAM, it wins the competition dueto high Rambus channel throughput. And although SDRAM can boast lower latency, it can't provide thesame fastness when transferring large data pieces. And with the MTH used in i820 the latency is alsorestricted by Rambus channel, which connects the chipset and the hub, and the throughput can't growbig because of SDRAM. Besides, the time needed for requests translation also tells. And in the endyou get the lag.

The results shown by i820 based system with SDRAM are similarly low in the next test as well, whichis CPUMark99, working with small pieces of data:

And now let's pass over to real applications:

Here the system on i820 with SDRAM performs on the same level as all the rest.

This new test package takes the system performance according to Adobe Photoshop 5.0, Adobe Premiere5.1, Macromedia Director 7.0, Macromedia Dreamweaver 2.0, Netscape Navigator 4.6 and Sonic FoundrySound Forge 4.5. Here the system on i820+SDRAM proved 13% slower than that on i440BX.

Now let's take a look at i820+SDRAM in games.

Here Supermicro SCD performed 10% slower than i440BX based mainboard.

No serious changes here. i820+SDRAM keeps disappointing us.

As in all the previous cases, i820 based system with SDRAM shows the worst performance of all.So, even though i44As in all the previous cases, i820 based system with SDRAM shows the worstperformance of all. So, even though i440BX doesn't support AGP 4x mode, i820 still fails to takeadvantage of this fact and to defeat its competitor.

Conclusions

First, a few words about i820 based systems with SDRAM in general. When we look at the testing results the conclusioninevitably comes to mind. If you hunt for speed, then i440BX is the best choice. If you can't wait to get the new featuressupport, such as 133MHz system bus and AGP 4x, then you'd better take a board on VIA Apollo Pro133A. If you have a lot ofmoney and you can't decide what to spend them on, then take a system on i820 with RDRAM. And as far as the combo ofi820+SDRAM is concerned, you'd better forget about it once and for all, because it proves awfully slow in all sorts ofapplications: gaming as well as office.

And now about the mainboard tested. Of course we can't blame Supermicro for Intel's inability to provide an acceptableprice to performance ratio in its new chipset. Besides, the microprocessor giant doesn't have any other mass products tooffer. And Supermicro simply launched its mainboard on a new chipset from Intel.

Highs

• Stability;
• 133MHz FSB and new Coppermine processors support;
• AGP 4x support.

Lows

• Extremely low performance;
• Poor overclocking opportunities.

Table of contents: Specifications MTH Closer look Overclocking Performance Conclusions