vt(4) driver problems on old Radeon cards

[Scott Bennett]

     I recently changed from one ancient computer to another, slightly less
ancient computer.  The older one had a Nvidia card that's no longer supported
by the current driver, but still worked with a separately supported, older
version of the driver.  The less old one has two Radeon HD 3870x2 cards hooked
together with a Crossfire cable and uses the KMS driver modules.  The change
has caused me considerable grief, as well as disappointment.  Some of the
grief is because xscreensaver apparently has a bug that causes it to fail when
the "blank screen" is activated on this hardware.  (I did send a bug report to
the author's email address per the instructions on his web site, but have thus
far received no response whatsoever.  I'll wait a few more days before
attempting to file it on the FreeBSD bugzilla under x11 stuff.)  The
disappointment is that, although the Radeon HD 3870x2 cards supposedly support
ATI Streams programs, which AMD apparently no longer does, they don't support
OpenCL.  I don't know what they lack for OpenCL.  Sigh.
     Other grief comes, possibly, from the vt(4) console driver. The sc(4)
driver results in the loss of a console upon either a) shutdown of Xorg or
b) an attempted virtual terminal switch away from Xorg.  That has long been
documented and was the impetus for development of the vt(4) driver.  However,
on this system, vt(4) has the same problem.  Further, the system's power
requirement, as well as its heat output, appears to increase by 20% - 40% when
using vt(4) compared to sc(4).  I haven't proved to my own satisfaction that
this seeming relationship is accurate, but should be able to do so upon the
next reboot.  A search of the archive for this list turned up a few postings
within the last month or two by people reporting higher power consumption when
using vt(4), but no one seemed to know why it was happening.  The higher
temperatures show up in the CPU, not the GPU(s), according to those postings.
I see very high CPU temperatures with vt(4), but don't recall what the
temperatures were when using the sc(4) driver, and I don't how to access the
GPU temperature sensors if any such exist.  (I don't know whether they do.)
If anyone knows of a utility to display GPU temperatures, please let me know.
     Also, if anyone has more information on the above described vt(4)
problems, I would appreciate whatever he/she can tell me.  Thanks in advance!


                                  Scott Bennett, Comm. ASMELG, CFIAG
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