Rebuilding the Studio PC (Design)

My studio PC is an old home-built dual 1.7GHz Xeon box: very hot, very noisy and not that powerful. It was built in the last century (1988) and has been modified a few times either because parts died (such as the PSU, monitor) or in various attempts to soundproof and quieten it. It has two large hard drives that are also very noisy. It also has lots of fans and an oversize (700W), inefficient PSU with another noisy fan. It is enclosed in a big tower system that only just fits under the desktop. The tower is quite loose fitting and rattles a lot. Have I mentioned that it is very noisy and, if so, could you hear me over the noise?

I decided that it was time to bring it into the 21st century. My first thoughts were to simply adapt the existing platform, upgrading parts on a piecemeal basis as I had before, but I quickly figured that this was not going to get me where I wanted to go, so I decided to do a ground up re-design.

For music, the PC mainly runs Sonar 2.2 XL and other sound tools such as Kontakt II, Acid, SoundForge and CoolEdit. This software uses a lot of CPU power and is memory and disk intensive. The dual Xeons are OK, but a bit dated now. I have 1GB of RDRAM memory on the machine. The SCSI disks are pretty quick, but the integrated SCSI controller only supports U160s. As far as upgrade is concerned, I am limited by the motherboard (a Supermicro P4DC6). The board was good in its day, but is now a bit outdated and has been discontinued by the manufacturer. I am maxed out on RAM both in number of slots and speed (400MHz), the SCSI is limited to U160 and the CPUs cannot be upgraded either in speed or to dual-core versions.

For music hardware, I use three PCI ports for sound stuff:

The SW1000XG and daughter card are used to generate sound that is sent to the rack as SPDIF (24-bit, 44.1KHz). Other pages on this site describe the rack in detail. Sound is fed back from the rack to the mixer as 8-channel 24-bit, 44.1Khz ADAT. The mixer mixes it with internal PC sound sources, such as Kontakt II. From there, I do my mix-down to disk. Everything is entirely in the digital domain. For monitoring, I take the SPDIF output from the mixer to an Extigy box, which I use as a DAC. I don’t really use the mixer to control mix levels, just to mix the signals from the devices. I control the level at source through MIDI. This allows me to control the whole system from Sonar. The mixer has some on-board FX that I use, but at preset, unchanging levels just to put a bit of warmth into the overall mix. The AX16-AT is used to get the ADAT output of my sound rack into the mixer. It cannot operate above 40ºC and so I have a constant battle keeping the overall temperature low.

To control the hardware in the rack, I use a Midisport 8x8, so there is a USB cable from the PC to the rack.

On the plus side, I don't run games and so my graphics requirements are very straightforward. I currently have an old 3D Prophet III (with yet another fan) connected to an AGP port. The graphics drivers from nVidia crash occasionally, but I have never been able to work out what causes it or to reproduce it reliably. My monitor is a Dell 2001FP 20” TFT, which is fine.

I use Nero for burning CDs and have a Plextor PX-740A ATAPI DVD+/-RW burner and I am happy with that as well.

I also do some software development (work) from home. Apart from running compilers and other development tools, I use VMWare as a test tool. To do this, I need a fast (preferably dual or dual-core) CPU, lots of memory and reasonably quick hard drives. I use the usual office tools for writing and drawing and a browser for the Internet. The PC is connected to our house network using a 100Mb switch and the switch is connected to the Internet via a firewall using cable (256Kb up, 1Mb down). Finally, I have anti-virus and other system-level tools.

The Design

My initial goals were to build a PC that was:

My desire for small, quiet, powerful PC led to me to start looking at a bunch of technologies such as Mini-ITX, Shuttle, SFF, HTPCs, MODT (Mobile on the Desktop), Epia and so on.

One of my key goals was noise reduction. Ultimately, noise is about power dissipation. Generally, the more power you apply to a CPU, the faster and hotter it runs and the more powerful the thermal solution required to keep the CPU within its working temperature range. There are a number of ways you can reduce the power requirements. One is to lower the CPU speed. This is what VIA do with EPIA range of processors. However, I need the raw CPU power, so this is not the way to go. Another way is to reduce the voltage of the CPU or to use lower voltage components (this also tends to lower the speed). Technologies like Intel SpeedStep (EIST), achieve their effects by adjusting speed and voltage on the fly, reducing power usage and temperature. However, to use SpeedStep you need the motherboard, CPU, BIOS and operating system to support it. I looked at low voltage Xeon designs, but they are very new and mainly targeted at the server market where quiet designs are less of an issue and do not support power saving features like “SpeedStep”.

I have considered buying a top-end desktop CPU and concentrating my efforts on creating a noiseless cooling solution, but, in the end, you still have to dissipate heat and so the choice of water or air-cooling is still a trade-off of one kind of fan with another. Yes, I know you can get fanless water-cooling devices, but I also have an innate and, possibly, irrational distrust of water-cooling. I have visions of liquid leaking out into the machine or all over the floor. I don’t do the plumbing around our house for the same reason. What I wanted to do was get to the heart of the problem and reduce the power requirements of the system as a whole.

I particularly looked at mobile technologies. Mobiles are specifically designed to give good performance in a low power environment, so that seemed the way to go. Now, generally, you can't buy mobile motherboards, but there are a number of manufacturers building desktop motherboards that can employ mobile CPUs (Pentium M, Core Solo, Core Duo). The main ones are Asus and AOpen.

Expandability is an issue for me. Although I wanted a small system, it needed to be big enough to accommodate the music hardware I use. Many of the smaller motherboards (mini-ITX, shuttle), only have one or, at most, two PCI slots and do not allow for this degree of expansion. I decided to review what the internal boards were giving me in my current system. I would not want to lose the SW1000XG or PLG150-DX boards as I have a number of pieces of music that rely on them. I briefly looked at ways to move these to a rack module. On possibility is the Kenton PlugStation, but I don’t think they make them anymore. Obviously, I could look for a second hand MOTIF Rack, but that is too expensive as a solution for me. However, I am able to replace the DSP Factory set with a single more up to date card. I need to take in ADAT, so either an Emu 1212M or an RME DIGI9636 would do the job. Another benefit of this approach would be that, since the AX16-AT has a strict temperature regime, losing it eases one of my many current thermal issues. I chose the Emu board because it allows me to use on-board DSP resources to create effects similar to the FX processor on the current mixer card. Also, it would give me additional upgrade paths such as Emulator X or adding an AudioDock (power permitting). So, in my new design, I need at least 2 PCI slots, one for the SW1000XG/PLG-150DX and the other for the Emu 1212M.

As I said, my old system had two SCSI hard drives, both quite noisy and expensive. I decided that my new system would employ SATA because I can purchase low noise hard drives at low cost that are quieter and cooler, but would still give me the speed I need. I chose the Samsung SP2504C, a 250GB/8MB 7200RPM drive that is generally recognised as one of the quietest on the market (28dB max). I would no longer need SCSI and this would simplify the design. I would also re-use my Plextor DVD+/-RW for burning ROMs. So, the new motherboard would need to support both SATA and IDE.

One of my requirements was to minimise cabling. Most of the cables are between the PC and the rack, so I decided that I would locate the PC in or on my rack. I investigated rack cases, but these are generally:

Instead, I would get a small case and place it on the shelf at the top of the rack. I would reduce the cabling by connecting the PC to the USB hub on my monitor and getting a USB keyboard and mouse connected to the monitor. The only downside of this is that it means the monitor has to be turned on before the PC. This way, the only cabling between the rack and the desktop would be USB and DVI with the network connection connected to our switch. So the PC must support at least 2 USB ports, one for the desktop connection and the other for connection to my MIDISport 8x8. I would connect the PC to the power supply on the rack and a LAN connection to the house switch.

So, in summary, I am looking for a fast mobile CPU on a motherboard, with at least two PCI slots and supporting internal SATA and IDE and external 2xUSB and 100Mb LAN connections.

I have got used to my dual machine over the years and wanted to stay with multiple cores. This led me to the Intel Core Duo (Yonah). This is a relatively new CPU (Jan ’06) designed for mobiles though usable on desktops, running dual core at speeds beyond my existing setup. This would give me the speed I need and a much lower power envelope. Another benefit of Core Duo is that it is built using Intel’s 65nm technology. Smaller gate lengths require less power to run and therefore run cooler. The problem with Core Duo is that it requires special chip socket and chipset. The socket is a 479-pin socket like the Pentium M, but with a different pin out. The chipset is the Intel 945 Express. I would need to purchase a motherboard specifically designed for this chip.

Standard voltage Core Duo is rated at 31W compared to over a 100W for Pentium EE. The low voltage versions would be better at 15W, but:

So, the solution appears to be to use a standard voltage Core Duo. The chip retails at approx. £320 for the 2Ghz version (T2500) and £480 for the 2.16GHz part (T2600). I decided the difference in clock speed was not worth the difference in price and went for the T2500. Apparently, Intel indicates that the Core Duo will be upgradeable to the Merom later in the year, which is good. Merom will work faster and cooler, support EMT64 and have some other goodies. Whether the motherboards currently available would support the upgrade is still unknown.

I worked through the Intel documentation for the Core Duo and 945 Express chipset making sure I understood the differences between the various chipset variants. I then reviewed the Core Duo desktop motherboards and chose the AOpen i945GTm-VHL board on the basis of size, availability and chipset configuration. This motherboard supports Core Duo using the i945GT GMCH (Northbridge) with an ICH7-MDH I/O Controller (Southbridge). By utilising the i945GT variant, I was hoping to be able to rely on the on-board graphics (Intel 950 running at 400MHz). In this way, I could avoid having to have a separate graphics card and so keep the system cooler. The i945GM variant has lower spec built-in graphics (250MHz) and the i945PM version has no built-in graphics at all. However, I was still not sure if this would be up to my needs, so I wanted the option of adding a low-end graphics card later, if needed. The AOpen board has a PCIE x16 slot for just this purpose. It also provides the graphics output as VGA and DVI and S-Video which suits my monitor.

The board uses SO-DIMM DDR2 memory, which is a bit more expensive than standard DIMMs. However, compared to my current system that uses RDRAM, it seems quite cheap. When buying DDR2 RAM, you need to get a matched pair. Matching them is important because allows the chipset to make optimal use of the available memory bandwidth. Since the motherboard only has two slots, I decided to go for the maximum amount of memory I could get because if I needed to upgrade in the future, I would have to replace the memory. I chose a matched pair of Corsair VS1GSDS533D2. These are 533MHz 1GB parts (2GB total).

The board also sports two PCI slots, on-board networking, 2 SATA ports, 8 USB ports, IDE and the usual other I/O. In other words, it has everything I need. In addition, it has a PCIEx1 slot, but I won’t need that.

The AOpen board uses a µATX form factor so I would need a new case for it. As I said, I wanted a smaller PC that would fit on my rack. I looked at the Silverstone SG-01 and the Antec Aria. I chose the Aria because:

The smartcard reader built into the Aria is handy for me, as it will ease backing up the smartcard on my Roland XV-5080.

On the downside, the PSU is not a standard ATX one and so is not upgradeable. I decided I could live with that. The PSU is based on Antec SmartPower technology. These are PSUs that adjust the fan speed according to the temperature of the power supply. In the Antec design, the PSU fan is also the case fan. Hot air from the inside of the PC is ventilated using the PSU fan. Unfortunately, Antec do not document the noise level of the fan. Actually, they do not document the 300W SmartPower PSU at all!

I had a concern that some reviewers had cooling problems with the Aria, though others did not. I rechecked the reviews where problems were reported. Generally, they were using standard high power desktop CPUs, fast graphics cards and generally packing the box with a lot of hardware reducing airflow, so it is not that surprising. The key to keeping the Aria cool seems to be to use fewer, lower power parts, so the PSU does not become hot and therefore does not have to spin up to cool the system. Well, that’s the theory; in practice, it’s another thing as we shall see later.

I then downloaded all the manuals and other information I could get my hands on. I did a rule of thumb calculation of the power requirements of the components (typical and maximum) to check that the Aria power supply could handle the board and to get a feel of the power dissipation I would have to deal with.

Motherboard (chipset)157
Motherboard (ext. devices)107
Emu 1212M155
Yamaha SW1000XG1010

It is very strange that very few manufacturers supply the power requirements of their components given how important this information is. So, some of the above are estimates. For instance, the Emu 1212M is rated at 15W when powering an external AudioDock. No rating is given without the external device. As I have no plans to use one of these, I expect its consumption to be considerably lower. The Aria PSU easily has sufficient power to support the hardware configuration. Assuming I deploy the PCI slot blower that comes with the Aria, power dissipation should be OK. If I am close to the envelope, I will add the optional fan mounting that is also provided.

Then I verified the design. I read every available review and forum and comparing against my own notes looking for problems. I kept a list of issues to be checked or resolved and added or removed items, as necessary. I downloaded all the manuals (even those for the memory and disk drive) and checked that there were no problems connecting the various parts.

First, there are the mechanical issues. How well would the parts fit in the box? From the motherboard and case manuals, I looked at the location of CPU and Northbridge (the hottest components) and checked how it would work within the Aria. Interestingly, AOpen have located the CPU in a slightly unconventional position that would assist in cooling because it would not be under the power supply but rather “out in the open” under the drive cage. Also, not using a graphics card would assist the airflow around the box. The width of the SW1000XG with its daughter card is always a bit tight, but I expect it to be no different in the Aria from the current PC since PCI slots are standard distances apart. The DVD and HDD are standard sizes that will just about fit. The box accommodates full-height PCI cards and the cards in question are not very long, so no problem there.

Then I checked each of the connectors matched up electrically. I find connectors fiddly and prefer not to have to customise them. All the connectors matched perfectly. I also considered the issue of cable routing within the box. The Aria also comes with a round IDE cable, which is good. I will be able to route most of the cables on the left-hand side of the box keeping them well away from the main motherboard components to avoid restricting the airflow. I would locate the slot blower over the PCIEx1 slot, which I don’t plan to use. I will need to purchase cable tidies and find a way of fixing them to the base of the unit. I plan to connect the front panel connectors down the left side of the box, pinning the cable tidies to the floor of the chassis. The power connectors will be taken down the right size and fixed in the same fashion. I will route the IDE and SATA cables through the drive cage and down to the motherboard with some slack so I can flip the drive cage easily. The wiring should be reasonably neat and should not restrict the airflow within the box.

The on-board audio provided by the chipset should be of a reasonable quality. The chipset provides HD audio and well as AC97. Generally, for my music work, I aim to keep the audio components of my system outside the PC unless I am dealing with purely digital signals. The PC environment is simply not conducive to analogue audio applications. I spent some time considering whether I could:

However, due to the locations of the various connectors I could not find any way to do this. I will probably connect the on-board audio to the front panel and connect the CD output to the motherboard and just have it to play CDs and DVDs. I will locate the Extigy box on top of the Aria and hook up the Emu1212M SPDIF output to the Extigy using SPDIF as I do now.

Air comes into the case via slots in the front of the case (these seem very small gaps to me). The air passes over the system board, first over the CPU heat sink and fan assembly and then over the Northbridge. Finally, it is sucked through the PSU and is expelled through the 120mm fan at the back. The fan has two cages, which also seems unnecessary, but should not impede the flow too much. In addition, the slot blower will draw air sideways and expel it at the back. I may need to experiment with this device as I am unsure whether it would be best drawing air from the Northbridge (where it is bound to create turbulence) or from the PCI devices where hot spots might develop. To do the latter, I would have to modify the blower though.

I checked the thermal requirements of the components to see if any have exceptional operating parameters. However, manufacturers are also very poor at providing temperature specifications. P4s generally operate up to 75ºC, but it is best to keep the CPU temperature well below this. I will aim at providing sufficient thermal solution to keep the processor below 50ºC and the case below 40ºC.

Next, I created a spreadsheet to calculate the costs of the parts.

CPUIntelT2500 318.00
HDDSamsungSP2504C 250GB63.32
KeyboardCherryCyMotion Expert - Black13.18
MouseDabsDabsValue Scroll Mouse USB Black2.93

The AOpen board is expensive until you consider that it has the graphics onboard. The CPU is also quite expensive, probably because it is a relatively new part. There will also be some additional small components such as cable tidies, a new wrist strap (my old one is a bit dog-eared), some rubber fixings and so on.

Cost is always a factor. Generally, building your own PC is simply not worth it for the standard configurations. You can generally get them off-the-shelf at a lower cost because of volume discounts. Also, it is frequently easier to buy a standard system and then modify one or two components to suit your needs. But, for the more exotic designs, you either cannot find a pre-built system or, if you can, they are more expensive to purchase. For instance, the only Core Duo based desktops on the market are Apple iMacs, which are of no use to me. The only other Core Duo systems are notebooks that would cost about twice the price and would not integrate with my rack because of limited expandability. As I said before, for me, building PCs is a bit of hobby, too.

The Specification

The final specification of the design is as follows:

2.0GHz Intel Core Duo CPU
2GB 533MHz Corsair DDR2 RAM
250GB 3GHz SATA Samsung SP2504C HDD
400MHz Integrated Graphics (Intel GMA 950) output via DVI, VGA and S-Video to Dell 2001FP 20” 1600x1200 TFT
Gigabit LAN via Cat5 TP cable
6x USB (2 at front, 4 at rear – 2 connected)
IEEE 1394 (Firewire)
Plextor PX-740A 8xDVD dual layer DVD+/-RW
Front panel Smartcard Reader
ADAT/SPDIF Digital Audio I/O
Front panel audio
USB Keyboard & Mouse
Dimensions: 20 (H) x 26,9 (W) x 33,5 (D) cm

If you are interested in what happened when I built the system click here