Albert Cahalan wrote:
Dan Williams writes:
You may want to update to the Q2B81 firmware which disables the branch
prediction workaround, and yields about 25% performance increase when
using any USB network devices (including the builtin wireless).
Uh, is that safe?
I thought that this was required to avoid causing errors in the
CPU's branch prediction history. Are we now just taking chances?
If USB got fixed to use uncached RAM, what about other devices?
_______________________________________________
Devel mailing list
[email protected]
http://mailman.laptop.org/mailman/listinfo/devel
Looking through the "AMD GeodeTM GX Processors Silicon Revision 2.1
Specification Update" (31533E_gx_2.1_specupdate.pdf) found the following entry:
1.36 Segment register misuse in AC stage of CPU execution pipeline
Is this the one underlying cause. Do you have a pointer to the issue?
Virtually every processor uses branch prediction to a improve performance.
Disabling the CPU's branch prediction hardware is a huge performance hit.
-Will
_______________________________________________
Devel mailing list
[email protected]
http://mailman.laptop.org/mailman/listinfo/devel
