Most of you were very impatiently waiting for a new Intel chipset - i815. A lot of hopes were pinned on this upcoming product, since Intel hadn't offered any other alternatives supporting SDRAM and aiming at mainstream systems for two years already. As for the competing core logic from VIA, they didn't make the mainboards as fast as Intel's chipsets.

So, finally the sacred day X has come. i815 was launched. However, it found very diverse welcome. On the one hand, this chipset really provides very high performance, which we have already proven in our i815 Chipset Review. But on the other hand, it costs much more than the already mentioned VIA Apollo Pro133A or i440BX. i815 received support from such a master as ASUS, which representatives kept stressing that i815 was a good replacement to the old buddy i440BX and promised that i815 based mainboards would remain the sales hit till the end of the year at the least. Without wasting its breath, ASUS immediately announced a couple of mainboards on this chipset, which have already started cropping up in retail. The major product in this family is CUSL2, which we managed to get for testing.

ASUS has always worked side by side with Intel that is why no wonder that it was ASUS, which was one of the first companies to launch i815 based mainboard. Here is the list of specifications:

Specification

• CPU
  • Supports FCPGA and PPGA Socket 370 Intel Pentium III 450-933MHz and up and IntelCeleron 333-566MHz and up
• Chipset
  • Intel 815E (Intel 82815 Graphics and Memory Controller Hub (GMCH), Intel 82801BAEnhanced I/O Controller Hub 2 (ICH2), Intel 82802AB Firmware Hub (FWH))
• System memory
  • 3 168-pin DIMM slots supporting PC100/PC133 SDRAM
  • Max supported memory: 512MB
  • No ECC support
• AGP
  • AGP Pro slot supporting 4x mode
  • AGP 4x graphics core integrated into the chipset
• Slots
  • 6 32bit PCI slots
  • 2 CNR slots (Communications Network Riser)
• I/O ports
  • 1 FDD port, 2 serial and 1 parallel ports, ports for PS/2 mouse and keyboard
  • 2 built-in USB ports and three additional USB ports (5 USB ports altogether)
• Integrated IDE controller
  • 2 IDE channels supporting ATA/33/66/100 (supporting up to 4 ATAPI devices)
• BIOS
  • 4Mbit Flash EEPROM
  • Award BIOS supporting Enhanced ACPI, DMI, Green, PnP Features and Trend Chip Away Virus and Symbios SCSI BIOS
• Other
  • STR (Suspend to RAM)
  • ASUS iPanel support
  • Hardware monitoring
  • Wake on modem, mouse, keyboard, LAN and timer
• Dimensions
  • ATX form-factor, 30.5x20.8cm

The mainboard is supplied in a maroon box. Together with the board you can find there a set of cables including a FDD cable, 40-pin and 80-pin IDE cables, a few spare jumper caps and two brackets set instead of the expansion cards into the rear panel of the case. One of them is intended for the second COM-port and the other is equipped with the three additional USB ports. Besides, you also get a CD disk with the drivers, ASUS PC Probe monitoring utility and Trend PC-cilin antivirus program. As a small gift from ASUS the package contains a sticker with a Pegasus saying "Powered by ASUS". And of course, a detailed user's manual, which has already become a tradition.

Closer Look

Since Intel 815 chipset is in the first place aimed at supporting Socket 370 CPUs and since Intel is equipping most of its CPUs with FCPGA form-factor, ASUS CUSL2 is equipped particularly with Socket 370. CUSL2 family also includes one more mainboard called CUSL2-M, however, this mainboard is also designed for Socket 370 CPUs and the only difference it has from the piece we are discussing today is MicroATX form-factor. The major advantage of i815 based mainboards compared to i440BX based ones is the official support of 133MHz FSB, which means that they have 1:2 AGP divider. And compared to mainboards on i820, they feature SDRAM support instead of the awfully expensive RDRAM. CUSL2 mainboard certainly boasts both of these advantages, but this is not enough for the piece to become the sales hit. Let's take a closer look at it before drawing any conclusions.

There are three DIMM slots supporting up to 512MB SDRAM on the board. To our great disappointment, the chipset, i815, doesn't support more memory and there is nothing you can do about it. However, since the memory bus of i815 is asynchronous, CUSL2 allows using the memory working at the frequency other than that of the FSB. This feature is activated via BIOS Setup, which allows clocking the memory for either 100MHz or 133MHz when using a CPU with 133MHz FSB. If the front side bus frequency is only 66MHz or 100MHz, the memory works at 100MHz. Though i815 has one more limitation, ASUS manages to overcome it in its CUSL2 mainboard. Here we mean the possibility to use PC133 SDRAM at 133MHz even if there are over four memory banks in the system. Note that the chipset specification claims that the memory frequency in this case should be 100MHz, not more.

Like all other mainboards from ASUS launched lately, CUSL2 allows setting the processor working frequency in two ways. To choose this or that way you need to switch a special jumper. The first way is jumperless, namely, you set the FSB frequency via BIOS Setup. By the way, we would like to draw your attention to the fact that setting via BIOS Setup is so flexible that you can change the frequency with the step equal to nearly 1MHz. The second way allows setting the FSB frequency with the help of a dip-switches set (5 dips). These dip-switches are located in front of DIMM slots. As for the clock frequency multiplier, Intel has been locking it in the CPU for a long time already that's why CUSL2 doesn't provide any means of changing it.

Since i815 is provided with an integrated graphics core based on i752, ASUS CUSL2 is equipped with a monitor out besides all other connectors on the rear panel. However, we have to admit that the graphics integrated into i815 can't boast extreme fastness that's why those of you who will decide on an i815 based mainboard will have to put up with the presence of one absolutely useless feature, which adds to the chipset cost and hence to that of the mainboard. But unlike other chipsets with integrated graphics, i815 supports external graphics cards and hence ASUS CUSL2 is equipped with a fully-fledged AGP Pro slot.

Although this slot is designed with a bit more pins than a conventional AGP slot, it is fully compatible with the ordinary AGP 1x/2x and 4x graphics cards. Putting it briefly, the main difference between this slot and the conventional AGP is the extra pins added to the AGP slot on edges and serving to connect 12V and 3.3V power circuits. These circuits should allow the graphics card to consume up to 110W of power. From the practical point of view, AGP Pro slot on CUSL2 allows using professional graphics cards with it. And in order to prevent the users from installing the ordinary graphics cards into this slot in the wrong way, the first 20 pins of a longer slot are locked with a special lid. Moreover, when using the integrated graphics, you can also install AIMM module into this slot. This AIMM is a 4MB 133MHz graphics cache.

ASUS CUSL2 is PC99 fully compliant and doesn't have any ISA slots. There are 6 PCI slots and 2 CNR (Communication and Network Riser) slots instead. CNR slots are an innovation introduced in i820E and i815E chipsets, which use ICH2 South Bridge. CNR slots are a further stage of AMR (which is incompatible with CNR, actually). These slots serve for software sound cards, LAN-cards, HPNA-cards and modems. However, bearing in mind that AMR hasn't been very beloved and demanded by the users recently, it appears pretty hard to imagine that 2 CNR slots are really necessary. But who knows, maybe they will be used for network needs later on. Full-size cards can be installed into three of the six PCI slots. The funniest thing about CUSL2 is that the last PCI slot is shared with one CNR slot, which resulted into the use of much thinner plastic slots.

ICH2 (Intel 82801BA) implements a few more interesting features. In particular, this controller supports new HDD interface - ATA/100 and so does ASUS CUSL2 mainboard. To make use of this new interface you need a hard disk drive supporting ATA/100 and an 80-pin cable, which goes together with the mainboard. ICH2 also allows implementing 6-channel AC'97 sound. However, the piece we had for review was provided with the layout for the two-channel codec only and no codec itself. That's why, we dare suppose that integrated sound is an optional feature, which is also mentioned on ASUS web-site.

Moreover, ICH2 supports 4 USB ports. But ASUS didn't want to be happy with this number and provided its mainboard with an additional Alcor Micro AU9254 USB Hub. Thanks to this hub ASUS CUSL2 acquired a riser-card with three more USB ports in addition to the conventional two USB ports typical of nearly all mainboards. This card is installed instead of any of the expansion cards into the rear panel. But this is not the end yet. There is one more connector on the mainboard, which allows adding another pair of USB ports, which makes altogether 7 USB ports.

As for the mainboard design, CUSL2 is not deprived of a couple of small drawbacks. First of all, ATX power connector is situated behind Socket 370, while it should be in front of the DIMM slots according to ATX specification. Another low point is the COM-port connector for the external COM-port, which is put to the front side of the mainboard. Since the bracket with the port included into the package is designed for the rear panel of the PC case, the cable will go across the entire case right to the rear side of it hindering air circulation. Besides, Clear CMOS appears also not very easy to carry out, because ASUS didn't provide its CUSL2 with a special jumper for this purpose. So, you will have to somehow close two contact plates.

The chipset North Bridge is equipped with a small green heatsink. And between the fourth and the fifth PCI slots you can see a green light emitting diode, which should signal when the PCI bus is under power. The main aim of this LED is to warn the user against installing/removing the devices with the power on. We have to stress that it is more correct connecting this LED to the PCI bus rather than to the memory power supply, which is typical of the whole bunch of other mainboards. The thing is that according to PCI 2.2 specification, PCI slots are powered even in stabdby mode, i.e. even when the system memory is de-energized.

As for the mainboard stability, ASUS CUSL2 proved impeccable. Nothing to be surprised at, actually: there are 11 capacitors of 1500uF each near Socket 370, which improve the signal quality. Besides, ASUS resorted to its old trick: the voltage in I/O circuits was increased over the nominal. It is set to 3.4V as default by CUSL2 while the usual nominal value makes 3.3V.

ASUS is keen on inventing different cool things. CUSL2 is also not an exception in this respect. This mainboard appears the first product supporting iPanel. iPanel is a device installed into the 5.25" section of the PC case. This device is equipped with 2 USB ports, 1 COM port, 3 Audio I/O ports, IrDA sensor, digital LCD indicator reporting about booting errors, voltages, CPU frequency, fan rotation speed and temperatures, and five indicator mode buttons.

The BIOS of ASUS CUSL2 is based on Award Medallion BIOS v. 6.0 and its interface is very similar to that from Phoenix. At the same time, the amount and functional peculiarities of the available settings make it similar to the classical Award 4.51PG. We should point out here that ASUS is still the only company, which provides its BIOS with a more or less informative Help, making clear a few things about the settings.

Hardware monitoring of ASUS CUSL2 is implemented as ASUS's own ASIC (Application Specific Integrated Circuit) AS99127F chip. The mainboard has 3 temperature sensors (1 external sensor). The information about the CPU temperature is taken from the on-die thermal diode. Besides, the mainboard controls 6 voltages and has 3 controllable cooler connectors. Moreover, CUSL2 is equipped with a chassis intrusion detector.

Overclocking

ASUS used to devote not so much attention to overclocking features. But now the situation has changed drastically and overclockers get more and more options with each new product. ASUS CUSL2 is none other but another move in this direction. It features SFS (Stepless Frequency Selection), which allows increasing the FSB frequency with the step equal to 1MHz.

So, you can set the following frequencies via CUSL2 BIOS Setup:

As you can see, the available frequencies range is just impressive. Look at 216MHz. Like that? Hehe, you will hardly be able to really enjoy it, because all modern CPUs have a locked frequency multiplier, and the memory, AGP and PCI frequencies are also increasing in a certain proportion. Nevertheless, we have never seen the supported frequencies as numerous as these ones before. Which is especially pleasing here, it's the possibility to set any frequency below 100MHz you like. It is really cool for Celeron overclocking, because there are no other mainboards featuring this option. We owe this incredible profusion to the new programmable ICS 94201CF clock generator.

As for the Vcore increasing opportunities, which are so important for overclocking, ASUS never forgot about them as well. CUSL2 has a corresponding option in BIOS Setup, which allows increasing the CPU Vcore up to 0.3V with 0.05V step. You can also increase the I/O circuits voltage, since CUSL2 has a special jumper, which helps set one of the following three values: 3.3V (nominal), 3.4V (default for CUSL2) and 3.6V.

Very useful thing for overclocking, particularly bearing in mind the difficulty with Clear CMOS described above, is a special booting algorithm: if the mainboard doesn't boot after you have changed some BIOS parameters, then the FSB frequency drops down to 66MHz and you get into the BIOS Setup automatically.

In real practice ASUS CUSL2 proved nearly the best mainboard for overclocking. 100MHz Intel Pentium III 600E taken for this test featured a new cB0 core stepping and overclocked up to 978MHz, i.e. up to 163MHz FSB, which is nearly by 1.5 times. Note that Vcore remained unchanged and equaled the nominal.

Performance

The testbed was configured as follows:

• Intel Pentium III 800EB (6x133) CPU;
• Creative 3DBlaster Annihilator Pro (NVIDIA GeForce256 DDR) graphics card;
• Creative Sound Blaster Live! sound card;
• IBM DLTA 307030 HDD;
• 256MB PC133 SDRAM by Micron.

We have already compared i815 chipset with all the others (see Intel 815 Chipset Review). This time let's compare the results shown by i815 based mainboards:

ASUS CUSL2 showed average performance among the mainboards of the same type. However, speed characteristics isn't the main argument when you choose a mainboard from a range of products based on the same chipset. The performances of different products differ so much, that you can't rely only on the benchmarks when selecting the right board. It's much more important to pay attention to the special features of a product.

Conclusion

So, new ASUS CUSL2 on Intel 815 chipset proved a high quality product with beautiful overclocking capabilities, high reliability and a set of rather interesting features. In particular, we should mention iPanel and 7 USB ports support. The only thing that can prevent you from buying this product for upgrade purposes is its really high price. But it is Intel, which you should blame for that, because Intel failed to make i815 a low-cost solution.

Highs

• 133MHz FSB, AGP 4x, ATA/100;
• High performance;
• Good reliability;
• Perfect CPU overclocking.

Lows

• High cost.