4 ms·

The IRS itself goes into detail: https://www.irs.gov/pub/irs-pia/imf_pia.pdf https://www.irs.gov/pub/irs-pia/imf_pia.pdf "IMF is located at the Enterprise Comp

The IRS itself goes into detail: https://www.irs.gov/pub/irs-pia/imf_pia.pdf https://www.irs.gov/pub/irs-pia/imf_pia.pdf "IMF is located at the Enterprise Computing Center – Martinsburg (ECC-MTB) and resides on the MITS-21 GSS. IMF is written in Assembler Language Code (ALC). There are no direct users of IMF. IMF receives data from an array of systems and then sends data to several systems as well." MITS-21 GSS == "Modernized Information Technology Services (MITS)- 21, IBM Master File General Support System (GSS)" https://www.treasury.gov/tigta/auditreports/2011reports/201120074fr.pdf https://www.treasury.gov/tigta/auditreports/2011reports/2011... There are two mainframe systems, Unisys and IBM: "The Unisys mainframe at the Martinsburg Computing Center processes all of the centralized Individual Taxpayer Information File workload for the 10 IRS campuses. The Unisys mainframe at the Memphis Computing Center processes all of the centralized Business Taxpayer Information File workload for the 10 campuses. The Unisys mainframe at the Martinsburg Computing Center is configured to run with 950 MIPS for normal weekday processing. For weekend processing, the Unisys mainframe at the Martinsburg Computing Center borrows MIPS from the development and test environments to increase capacity to 1,200 MIPS for managing the increased workload. The borrowed MIPS are returned to their respective systems on Monday mornings to support weekday processing. The Unisys mainframe at the Memphis Computing Center is configured to run with 675 MIPS for normal weekday processing." "In October 2010, the IRS upgraded its Martinsburg Computing Center mainframe computers from the IBM z/9-series mainframes to the IBM z/196-series mainframes." The report even provides nice utilization graphs.. Your government at work. edit: The type of Unisys systems "The IRS Unisys mainframe environment contains two Dorado 280 mainframe computers, with one located at the Martinsburg Computing Center and one at the Memphis Computing Center. Because vendor hardware support will be discontinued as of December 31, 2011, the IRS has decided to upgrade the Dorado 280s to Dorado 780s during Fiscal Year 2011."

quasse 10y ago
For anyone else who was curious, an Intel i5 2500k runs at about 83,000 MIPS compared to the 1,200 of the entire IRS Mainframe.
- microcolonel 10y ago
  They more or less just seem to be running tall sums, so I don't think it would matter much.
- sliverstorm 10y ago
  Main-frame specialty is crazy IO, I'm told, not raw muscle
  - jcrawfordor 10y ago
    Yes, the number of instructions per 'business operation' in a mainframe is typically much, much smaller than on something like an x86. This dates back to IBM's early habit of implementing all instructions in lengthy microcode, resulting in instructions that were relatively slow to execute but did complex things, typically taking an entire high level operation (e.g. sum all these numbers) and making it one instruction. A big part of making this happen is the IO model on mainframes which is much more integrated than x86 professionals are used to. In general files on mainframes are not binary blobs but schema-compliant tables similar to an RDBMS, a fact that is leveraged at a very low level when programming for mainframes. This leads to a very different kind of thinking from using microcomputers. I highly recommend that anyone in computing learn to use a mainframe or at least minicomputer operating system, which is affordable thanks to services like PUB400 from RZKH which provides free access to an IBM i minicomputer. Yes, these systems are uncommon today outside of certain specific market verticals (e.g. finance), but the exercise will show you a very different way of organizing a computer system that might help you think outside of the *nix-style box.

quasse 10y ago

For anyone else who was curious, an Intel i5 2500k runs at about 83,000 MIPS compared to the 1,200 of the entire IRS Mainframe.

microcolonel 10y ago
They more or less just seem to be running tall sums, so I don't think it would matter much.
sliverstorm 10y ago
Main-frame specialty is crazy IO, I'm told, not raw muscle
- jcrawfordor 10y ago
  Yes, the number of instructions per 'business operation' in a mainframe is typically much, much smaller than on something like an x86. This dates back to IBM's early habit of implementing all instructions in lengthy microcode, resulting in instructions that were relatively slow to execute but did complex things, typically taking an entire high level operation (e.g. sum all these numbers) and making it one instruction. A big part of making this happen is the IO model on mainframes which is much more integrated than x86 professionals are used to. In general files on mainframes are not binary blobs but schema-compliant tables similar to an RDBMS, a fact that is leveraged at a very low level when programming for mainframes. This leads to a very different kind of thinking from using microcomputers. I highly recommend that anyone in computing learn to use a mainframe or at least minicomputer operating system, which is affordable thanks to services like PUB400 from RZKH which provides free access to an IBM i minicomputer. Yes, these systems are uncommon today outside of certain specific market verticals (e.g. finance), but the exercise will show you a very different way of organizing a computer system that might help you think outside of the *nix-style box.