July 19, 2001

Review: Gigabyte 7DXR Athlon motherboard

Author: JT Smith

- By Jeff Field -

With new CPUs come new motherboards, and, of course, every motherboard maker wants to have a shot of being the king of these new CPUs. I recently purchased an Athlon 1.4GHz CPU, and the first board I am testing with it is the Gigabyte 7DXR.
The board
The 7DXR uses the AMD761 North Bridge from AMD. AMD seems to have a pattern - the company releases a new type of CPU and a chipset to go with it, and slowly lets third parties, such as VIA, take over. While there are plenty of other chipsets that work with the current Athlons, AMD put the 761 out this past year to move improvements forward, this time bringing DDR (Double Data Rate) RAM to the Athlon platform. For its south bridge, Gigabyte has opted to use the VIA686B from VIA.

To explain these terms, the north bridge controls the buses, such as the AGP, PCI, and memory bus, as well as the CPU itself. The south bridge controls the I/O, such as serial ports, USB, and the hard drives. Different bridges from different manufacturers can be combined for the best overall combination, because various "sets" have advantages and disadvantages that can be overcome by "mixing." For instance, the VIA south bridge allows for two more USB ports than the AMD south bridge that is normally paired with the 761 north bridge. The north bridge on the board is not only protected from heat by a heatsink, but by a fan as well. I suppose this makes sense, because these chipsets run faster than the old 486s that required heatsinks to run.

The board is not lacking in expansion capability, although it does not offer the most expandability either. The board has five PCI slots, bested by several other boards that have six. It comes with an AGPPro slot, which provides more power than the standard AGP slot for those cards that use it. It has three 184-pinn DDR slots, allowing for a maximum of 1.5 gigabytes of DDR memory. With 256 DDR modules going for as little as $45, a real "sweet spot" for this board would be 768 megs of RAM, maxing out the slots and giving you a ton of memory for around $135 right now. That's certainly not necessary to get the best performance out of the board, but with RAM, always get what you can afford, it certainly will not hurt.

For external expansion, the board has two serial ports, one parallel port, two USB and the PS/2 mouse and keyboard ports are on the rear. In addition, if you want to enable the onboard sound, a MIDI/game port is present as well as ports for line in, line out and MIC in. Also in the box, and this was a pleasant surprise, is another set of USB ports, which can fit into an empty slot on the back of the machine, bringing the total USB ports to four.

For ATA devices, the 7DXR provides four ATA100 ports, two of which belong to the onboard Promise IDE RAID controller, which can either provide IDE RAID or control four extra normal IDE devices. The RAID support is for either RAID mirroring (RAID 1) or striping (RAID 0), and the RAID setup is controlled from the Promise BIOS.

Also included on the board is Creative Labs Soundblaster 128 On Board sound. For those familiar with Ensoniq boards from a few years back, this is essentially the same thing. It's very low end, but for those who are not doing a lot of sound-intensive tasks, it is fine. If you are playing games, consider a better card, if you are just listening to MP3s, you will have no problems.

Layout and design
The 7DXR is laid out very nicely. The CPU socket has room around it so that the heat sink won't be in potentially damaging contact with other components on the board, and makes it very easy to remove and install the CPU/heat sink. The AGP slot does not have anything immediately behind it, allowing for those annoying cards that have extra pieces of PCB hanging down for no reason. The AGP slot also has a slight groove at the end of each slot for those 64-bit cards, which are difficult to install in a lot of 32-bit PCI slots. IDE layout is nice, with the ports for the two controllers far enough apart to reduce clutter. The only problem with the layout, and it is a slight one, is that two of the PCI slots can only accept short cards if the tertiary and quaternary IDE ports are used, due to their placement.

Documentation and configuration
The documentation that comes with the 7DXR, while never mentioning Linux specifically, is OS-independent enough for that not to matter. The documentation is well written and thorough, printed in a very thick manual. It will take you from installing the board to changing all the settings in the BIOS, even covering the RAID BIOS.

The BIOS on this board includes the ability to adjust the bus speed and core voltage for the motherboard, something not seen on all current motherboards. This feature is primarily targeted at those who want to overclock, and should not be used for those interested only in stability. The BIOS itself is well documented in the manual, and therefore, is very easy to use, and will be familiar to many users because it is a normal Award BIOS.

A feature that is (so far) unique to Gigabyte boards is their Dual-BIOS technology. Essentially, Dual-BIOS keeps two separate BIOS chips on the board, one of which is always dormant. If the one should be damaged because of a bad flash upgrade or other means, you can switch to the second BIOS. This may seem wasteful, but I bet that this has saved Gigabyte some money in the long run, because bad BIOS flashes are a leading cause for board returns.

System Specifications
AMD Athlon 1.4GHz
256 Megs DDR PC2100 RAM from Crucial.com
Western Digital 7200 RPM 10.2 Gig Hard Drive
3Com 3C905TX-C 10/100 NIC (PCI)
300 Watt AMD-Approved ATX Power Supply
Abit Siluro GeForce 2 MX400 64MB AGP

Kernel compiles
To test the board for both stability and speed, I ran Linux kernel compiles. Next to a compile of GCC, you will find little that stresses the RAM, CPU and motherboard more than a kernel compile. While running a total of 10 kernel compiles (the first five done with reboots in between, the last only with "make clean" in between to simulate heavy system use) the board did not crash once. I did the tests by answering yes to the default questions in "make config" for the kernel, and then running "time make -jN bzImage where N is the number of processes to create while compiling, normally used to make sure system resources are being used best, especially in multi-CPU systems.

Kernel compile times (Minutes:Seconds)

Gigabyte 7DXR
Build Type Kernel 2.4.6
1.4GHz - j1 4:28
1.4GHz - j2 4:20
1.4GHz - j3 4:21

As you can see, the kernel compile times for the 1.4GHz Athlon on this board with DDR RAM are excellent, clocking in at a little over four minutes. Kernel compiles really do not say much about motherboards, most tend to perform similarly, but they will point out problems between chipsets, such as differences in memory latency and bandwidth. In this case, the 7DXR comes out quite well.

The 7DXR from Gigabyte is certainly an impressive board. It is packed with features, from expansion to reliability features like Dual-BIOS. For those looking for a reliable DDR board with lots of features, seriously consider the 7DXR. It is an excellent board from a reputable manufacturer with a clear eye for reliability. The 7DXR is available on Pricewatch for $189.


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