nullstream weblog - SFF AMD64

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January 2, 2005 03:02 PM PST

Last week we built a Small Form Factor AMD64 machine. AMD64 is really at not only the peak of performance, but also of price. Intel based machines have really been taking a beating this year. Intel tried to add the x64-64 extensions to their high-end P4s, but the results were super expensive and performance worse than AMD's standard solution. The AMD64 chips are also much cooler, making them a better solution for small form factor, silent PC and overclocking.

So much is written about 64-bit machines being able to address more ram. But for some reason, marketers haven't pushed the primary home user advantage - faster math operations. Operations on 64 bit integers bit integers happen natively, giving up to 4x performance over standard 32 bit architectures on operations such as multiplying two 64 bit ints to a 128 bit int. Intel's SSE2 extensions do allow 64 bit operations, but these must be hand coded in assembly. 64 bit compilers will automatically take advantage of the increased precision. Also, since the registers are all larger, the register space is effectively doubled, providing much faster access to common variables than the slower, more expensive cache.

The cool thing is, AMD64 is the best performing PC architecture, but we haven't seen its full potential. Until Windows XP x64 is released (scheduled mid-2005), we won't see the OS, or any applications compiled for the new processor. That means that we should see a significant boost in applications once the Microsoft compiler for x86-64 is available.

Here's a great overview of AMD64 performance. To view the charts (in the black squares), you must select the text - there's a bug in their HTML code. Tests were done on 32 and 64 bit linux on the same processor, showing the massive gains in 64 bit mode. Also for comparison, they completely trounce the "equivalent" P4 3.2ghz. Example:

CPURSA 1024 bit digital signatures per second
P4 3.2GHZ147.2
AMD64 3200+ 32 bit mode207.3
AMD64 3200+ 64 bit mode913.8
Get ready for huge performance improvements to game engines and audio/video encoding when XP x64 is available.

Read on for the specs, photo and current pricing of this bad boy. sk83g.jpg

Prices are from, mid December 2004.

Shuttle SK83G SFF System$199
Athlon64 3000+ Newcastle 754 Pin Retail$151
2 x 512MB PC3200 Corsair Value Ram$144
Lite-On SOHW-1633S Dual Layer DVD Burner Retail$64
Maxtor 160GB 7200RPM HDD$79
MSI GeForce 6600GT AGP$215
Shipping & Tax$30

I feel that for a SFF machine, this is about the best deal there is. Shuttle is well trusted and has a cool heat-pipe system for cooling which reduces the number of case fans. For $199, a SFF AMD64 system with 240 watt power supply and everything (even video) on the motherboard is a great deal. Shuttle has more expensive AMD64 machines, but the performance doesn't justify the cost. The only peripheral missing from this SFF is gigabit ethernet, but then again, most people aren't running gigabit networks yet, and you can always add it as a pci card. I would no longer recommend SFF systems for people that don't care about the transportability of the machine. There are lots of quiet, expandable towers available now with heftier power supplies and better cooling.

The 754 pin 3000+ is the best price/performance now, although that is constantly changing. The 939 pin chips are "the future", but the dual channel memory (the reason there are all those extra pins) doesn't really provide much of a performance improvement to make it worth it.

The nice thing about the single channel memory controller on the 754 pin CPU is that you don't have to buy a pair of RAM sticks. So you can actually keep costs down and stick with just 512MB, which (while minimal) works pretty well. We opted for 1GB, and it was cheaper to get these as a pair.

This case supports only one optical drive, so we got it all. The prices are so low for an all-format drive that it only makes sense. Lite-on has been a favorite of mine for years ever since it scored the higest in storage-review's digital extraction tests.

From my perspective, there are two ways you can go with HDDs. Either a 7200rpm 8MB cache drive 160GB or larger (250GB prices are rapidly dropping), or a small (74GB) SATA 10,000 RPM Raptor. For home use, a larger drive is typically better and for development work, nothing beats a fast HDD - compiling is primarily bottlenecked by disk speed, as are massive searches, etc. through code. This time we just chose whatever HDD was on sale locally < $100.

The video card choice depends a lot on what the machine is used for. The built in video would be fine for 2D work, and basically any development/Web browsing tasks. When it comes to 3D on AGP based systems, the NVidia GeForce 6600GT is the undisputed price/performance leader according to many tech web sites. It is the only card in the $200 range that can handle HL2 generation games at full effects and high resolutions. The next step up is in the $350 range for the GF6800 series and the ATI X800 family.

XP Pro. I would reccomend a completely different AMD64 system for Linux. You'd want to go with a very popular motherboard with onboard video that was confirmed to have drivers for all onboard peripherals, and skip the dvd burner and video card.

This machine is well designed and pretty quiet when at low load. At higher load (an hour of HL2), the smart-fan revs up a bit, but it's not noticable above the game sounds. If you're a huge Seti or UnitedDevices nut, I wouldn't recommend a SFF system, as they can get pretty loud if the CPU is at 100% for long periods.

The video performance is great - most games should run at 1280x1024 resolution with no problem. We saw some choppiness when interacting with characters in HL2, and ended up turning the rez down a notch. This particular video card has an overclocking control panel that will boost performance by up to 10% which may well get rid of the occasional choppiness. We did have a very frustrating issue with an apparent grounding problem and the video card, but once we re-attached all the cables to the motherboard, the system seemed stable.

I'd reccomend this machine to anyone looking for a nice, fast and cheap SFF machine.
Comments (1)

J, January 4, 2005 12:20 AM:

This machine also has SPDIF in and out, as well as s-video. It's cool, but who has an SPDIF source switcher on their AV receiver? How are people hooking xbox, dvd and SFF all with optical out to their surround system? Would something as dumb as a plastic/glass multiplexor clip work as long as you didn't play more than one signal at a time?

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