Re: [RFT] Port 0x80 I/O speed

[Mike Lampard <mike@secnet.net.au>]

On Wed, 12 Dec 2007 10:01:18 am Rene Herman wrote:
> Good day.
>
> Would some people on x86 (both 32 and 64) be kind enough to compile and run
> the attached program? This is about testing how long I/O port access to
> port 0x80 takes. It measures in CPU cycles so CPU speed is crucial in
> reporting.
>
> Posted a previous incarnation of this before, buried in the outb 0x80
> thread which had a serialising problem. This one should as far as I can see
> measure the right thing though. Please yell if you disagree...

cycles: out 1399, in 303
cycles: out 1347, in 297
cycles: out 1235, in 251
cycles: out 1342, in 249
cycles: out 1393, in 274
cycles: out 1241, in 261
cycles: out 1238, in 251
cycles: out 1383, in 277
cycles: out 1228, in 252
cycles: out 1413, in 303
cycles: out 1394, in 268
cycles: out 1378, in 292
cycles: out 1239, in 265

 -m32 build on x64
processor       : 1
vendor_id       : AuthenticAMD
cpu family      : 15
model           : 107
model name      : AMD Athlon(tm) 64 X2 Dual Core Processor 4400+
stepping        : 1
cpu MHz         : 2300.000
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