# Computing charges memo

Your statements of Math Faculty Computing Facility (MFCF) charges for each month are found at MFCF monthly statements. They are computed according to the formulae included in the statement.

A copy will also be mailed to you  monthly. These statements list the computers you own based on MFCF sponsorship records.

Changes or corrections to your listing should be reported to mfcfaccounts@uwaterloo.ca.

By default, you will be billed at the end of each term for charges accrued during the term, as shown in your monthly statement. As a convenience, you may arrange to have the amount of your statements automatically deducted from a grant. Automatic billing does not mean that errors can not be corrected provided they are brought to our attention promptly.

## Summary of the charging algorithm

The cost of MFCF support for a given piece of equipment is 50% (the "Dean's subsidy") of the actual measured average cost of maintaining that category of equipment.

Charging algorithm is designed to be revenue neutral.

### Computers

You may decline computer support. If you choose support later on, you must sign up for a minimum of one year and your equipment must be in working condition. Or, you may choose to take your equipment to the CampusTech shop and pay an hourly rate.

MFCF will install and set up your machine as long as you sign up for a minimun one term of support, or you may sign up for ongoing support.

Here are the monthly charges for a few common single-user computing platforms:

Platform Cost to MFCF ("A") Dean's subsidy Cost to you
Windows $58 50%$29.00
Clusters $200 (head)$25 (node) 50% $100.00/$12.50
Macintosh $58 50%$29.00
Linux $55 50%$27.50
X-terminals $19 100%$00.00

These numbers are reviewed annually.

Multi-user computers are billed according to the following formula:

A + 0.65 * A * ( N - 1 )0.7

where A is the base cost of the machine when unshared (per the above table) and N is the number of active users during the month in question. This charge may be allocated in two ways: (1) it can be forwarded to a representative of the group, which may determine each user's charge in any manner it chooses and arrange for payment; (2) alternatively, MFCF is willing to bill individual users directly, in which case half of an individual's bill is based on central processing unit (CPU) usage (a measure of active machine use) and half is based on disk usage. [1]

The formula for "clusters" of like-minded computers managed as a unit (such as the research Unix environment) is more complicated, but should result in somewhat lower charges; see the MFCF billing algorithm.

MFCF will not charge for supporting the Mac minis provided to graduate students by the Faculty.

Please review the list of machines you sponsor and notify mfcfinventory@uwaterloo.ca of machines that fall into this category.

## Staff computing support

MFCF provides computing support free of charge for administrative staff. Computing support for staff hired to support research is chargeable.

## Networking

Each faculty member is entitled to free network connections (IP address)for themselves and grad students.

## Printing charges

The cost of printing: $0.10 per single-sided page and$0.15 per double-sided page. There is no subsidy for printing.

[1] Actually, the square roots of CPU and disk usage are used. A given user's fraction of the charge is proportional to the ratio of the square root of his/her usage to the sum of these square roots.