Osprey reliable and cheaper to operate

Commodity priced devices (disks, printers, cartridge tape drives, etc) replace the traditional minicomputer peripherals. The high mean-time-between-failure figures for commodity PC devices, coupled with the low cost of the devices themselves puts PC users in an entirely different repair and maintenance mode.

Lower power consumption for today's modern PC technology translates into lower cooling costs and dramatically lower electricity costs; dramatically smaller system footprint saves floor space, and that translates into lower space costs.

Suppose we make the following assumptions:

• Maintenance on your PDP-11 is $5,000/yr.
• Floor space is valued at $25/sq ft/mo, or $300/sq ft/yr.
• The Osprey/PC costs you $20,000.
• The Osprey/PC uses 5 amp @ 115v (.5 kw).
• The PDP-11 uses 100 amp @ 115v (12 kw).
• Electricity costs $.06/kw hour.

We can calculate some cost difference figures as follows:

Power

• Power for PDP-11 = 12 kw/hr
• Power for Osprey/PC = .5 kw/hr
• Assuming 24 hour a day operation year round, this translates to a yearly savings of $6,050 for the Osprey/PC over the PDP-11

• Yearly PDP-11 maintenance cost of $5,000
• Typical Osprey/PC maintenance cost of $1,000
• Savings, Osprey over PDP-11 of $4,000/yr

• PDP-11 floor space of 3 x (2.5' x 1.67')
• Osprey in rack mount chassis (2.5' x 1.67')
• Difference of 8.35 sq ft
• Savings, Osprey over PDP-11 8.35 x $300 = $2,505

• Depreciation on PDP-11 is none. It is fully depreciated.
• Assuming 3 year depreciation program, depreciation on Osprey of $6,667
• Savings, PDP-11 over Osprey, $6,667.

• Three year savings for Osprey = 3 x ($2,505 + $6,050 + $4,000 - $6,667)
• Over 3 years, the Osprey has saved $17,664.