Size Modifiers for Computers?

[ehrbar]

I was trying to figure out the costs for Awaken Computer (directly and as an enchantment), and that spell, as a Regular spell, interacts with the Size Modifier rules.

So, looking at the sizes in Ultra-Tech and High-Tech:

• The personal (Ultra-Tech, p.22) or medium (High-Tech, p.20) computer and smaller seem to be pretty obviously SM 0 or less.
• The microframe is "cabinet-sized" -- how big a cabinet, and is it a box or an elongated box or what? I'm imagining anything from SM +0 to maybe SM +3 could be justified here.
• The mainframe is not given a comparative size; the weight (400 lbs.) is ten times the weight of a microframe.
• The macroframe similarly is not given is not given a comparative size; the weight (4,000 lbs.) ten times the weight of a mainframe or a hundred times that of a microframe.
• The megacomputer is "the size of an entire building" (Ultra-Tech) or "fills a whole building or a series of subbasements". Its weight is given as 20 tons (ten times the macroframe, a hundred times the mainframe, a thousand times a microframe).

Is this nailed down any more precisely anywhere else?

[Stormcrow]

The microframe is "cabinet-sized" -- how big a cabinet, and is it a box or an elongated box or what? I'm imagining anything from SM +0 to maybe SM +3 could be justified here.
The mainframe is not given a comparative size; the weight (400 lbs.) is ten times the weight of a microframe.

A microframe needn't have any particular shape; different genres will envision them differently. Generically, imagine a small dresser. Bigger than a personal computer; you could lift it by yourself, but you'd probably be better off with a dolly. Probably between SM-1 and SM+1.

A mainframe is equivalent to a whole row of microframes. Probably around SM+2 or SM+3.

Remember that computers can be Compact, Hardened, Printed, Quantum, and/or FTL (TL11^), which will modify the weight, and possibly therefore the Size Modifier.

[Pursuivant]

On another thread, a reasonable formula for SM based on mass for living creatures was:

Size = LN(Mass/250 lbs.). Setting the number to something more appropriate for a Size 0 machine (e.g., 500 lbs.) might get you in the ballpark.

If that seems too math-heavy, look at the description for the item. Something like a mini/wearable computer or smart phone is likely to be Size -7 to -6. A laptop-sized computer will be Size -5, desktop/personal Size -4 to -2 depending on form factor. A mini-frame is going to be -1 to 0, etc.

[Varyon]

Originally Posted by Pursuivant

On another thread, a reasonable formula for SM based on mass for living creatures was:

Size = LN(Mass/250 lbs.). Setting the number to something more appropriate for a Size 0 machine (e.g., 500 lbs.) might get you in the ballpark.

If that seems too math-heavy, look at the description for the item. Something like a mini/wearable computer or smart phone is likely to be Size -7 to -6. A laptop-sized computer will be Size -5, desktop/personal Size -4 to -2 depending on form factor. A mini-frame is going to be -1 to 0, etc.

The vessels designed with GURPS Spaceships are probably lower density than computers, but aren't a bad jumping-off point. For that, SM+0 is 0.1 tons (200 lb), SM+1 is 0.3 tons (600 lb), SM+2 is 1 ton (2,000 lb), and so forth. If you assume most computers have roughly twice that density, for a 2-5-20 (or rather 4-10-40 when dealing with lbs rather than tons) pattern instead of the 1-3-10 one, the microframe (40 lb) would be SM-2, the mainframe (400 lb) would be SM+0, the megacomputer (40,000 lb) would be SM+4, etc.

[Culture20]

A modern 8U server (14 inches tall in a server rack)filled with heatsinks and fans is about 250 lbs. Double that to 28 inches tall, 19 inches wide (standard) and 37 inches deep, and you'll have something 500 lbs, and easily humanish size, albeit laying down.

[Tyneras]

GURPS Spaceships have densities around 1/3 to 1/4 that of water, since they include things like hallways and other open spaces. So good to model a building full of servers, not so great for modeling the computers themselves, which tend to be quite a bit more dense than water.

[ehrbar]

So, anyway, based on

1) The apparent GURPS High-Tech: Electricity and Electronics guideline of a GURPS 4 "microframe" being the class of a workstation or the original IBM PC, while a GURPS 4 "mainframe" is the same size class as a minicomputer (traditionally rack-mounted);

2) The fact that the reasonably-standard 42U rack is about six feet high while being an elongated box rather than of human proportions;

3) The order-of-magnitude increases in both list weight and "Complexity" with each increase in class suggesting that the linear dimensions between classes should increase at roughly the cube root of 10;

I decided to go with a "mainframe" being a single rack at SM +1, a "macroframe" being ten racks (or equivalent) at SM +3, and a "megacomputer" being a hundred racks (or equivalent) at SM +5.