On RAID arrays:
"stripe means just one big disc, so there is is no point in having two"
This is not the whole story, properly configured, a RAID array could significantly reduce your paging times.
Last time I looked at this, there seemed to be 4 or more standard arrangements of making a disk array, but when you think about it, there's only 2 basic principles:
1. duplicate the data on each disk - increase reliability & increase write / read times
2. distribute data over disks in order to increase write speed and reduce reliability by (at least) 50%.
If you want to reduce paging times, you'd want to choose option 2.
It's not necessary to have a hard disk on a pc - people have made systems with bootable flash drives. Paging to flash is much faster than to a hard disk, but there's no room for file storage, so you need a USB hard disk for file storage. The files are transferred to the flash area to be edited then copied back afterwards. Flash memory does start to fail after a given number of write cycles (depends on type 1000 - 1000,000 write cycles). Another tradeoff.
"somewhere, is the best best best thing say, 100Ghz triple processors with 100G of Ram and 10G hard drives......."
That's in the right direction but at least one order of magnitude away. Heavy duty calculations use clusters of computers & split the processing into chunks - each chunk being processed on a separate machine. SETI are using screensaver time on many thousands of idle computers to detect non-random patterns in EM data. Animation studios use render farms (clusters of networked computers) to perform ray tracing and image generation on each frame of a movie. Typically it can take one to several hours to render a single frame. Dreamworks have recently upgraded their kit and are now using upwards of 500 clustered Linux machines to create (in effect) a several THz machine with a 500+ core processor. It can render a single frame in 1/46 second. Dreamworks have this kit because they're probably using something like cinepaint to render 32 or 64 bit-per-channel images. I know it's not a feasible solution for a home / small business photo editor.
On water cooling:
Thermal management of the average desktop PC is dire. Fans are the most unreliable component in electronic / electrical systems (connectors win 2nd place). If that's not bad enough, fans collect and distribute dust.
There's an equation that describes how efficiently heat from a processor die gets to the surrounding air, it's just like ohms law:
heat flux = Temperature drop / thermal resistance
So, to get the maximum heat flow, you need to lower the thermal resistance.
The thermal resistance is made up of:
* die to package (can't do anything about this)
* package to heatsink (use good quality thermal bonding medium )
* heatsink to air (use a heatsink with large surface area & approximately double its performance by using a fan).
The weak link in this chain is the heatsink to air boundary, which, due to the large difference in thermal mass of metal and air is where most of the thermal gradient will be. It gets much worse over time as the fans coat the heatsink with dust, and the heatsink-to-air thermal resistance increases, then your processor gets hotter.
There are systems available with fanless processors, I've seen one that is thermally coupled to the case, which then acts as a very big heatsink. This isn't a new idea, it's been done in car radios (and many other types of equipment) for decades.
Blowing the hot air out of the case through the PSU isn't such a bright idea anyway, there are components in the PSU whose deterioration rate is exponentially proportional to temperature, and these are filtering voltage spikes out of the supplies fed to the computer's components. These age, the supply voltages get noisier & the components get hotter.
You can use fans with integral air filters that blow into the case. The case is then slightly pressurised with clean air, so the heatsink doesn't get contaminated with dust.
Water cooling gives a very efficient heat transfer from the heatsink due to the much higher thermal mass of water, and will give more reliable cooling, as long as you're careful to avoid leaks. It comes with the added benefit of silence.
Right there's me off the soapbox - I knew it was a mistake to drop by the tech help board - I'm off back to photo restoration.
