[Mesa-dev] [PATCH 0/7] vbo: introduce a minmax_index cache

[Marek Olšák]

On Fri, Jan 8, 2016 at 5:01 AM, Timothy Arceri <t_arceri at yahoo.com.au> wrote:
> On Thu, 2016-01-07 at 19:57 -0500, Nicolai Hähnle wrote:
>> Hi,
>>
>> this series is intended to address a (big) part of the performance
>> problems
>> that occur when games use an index buffer from a VBO together with
>> vertex
>> attributes supplied by user pointer. On a lower-end Radeon (Carrizo),
>> it
>> lifts This War Of Mine (the worst offender I've seen) from basically
>> unplayable
>> to an acceptable ~22fps.
>
> Hi Nicolai,
>
> A while back I added a SSE41 min/max optimisation for the INT path. I
> never added it to BYTE/SHORT as the games I was benchmarking never hit
> those paths. It would be interesting to know which path "This War Of
> Mine" is hitting.
>
> A quick Google shows Carrizo should have SSE41 right?

AFAIK, the biggest performance killer is the CPU-GPU synchronization
caused by mapping the buffer, not the min-max computation.

Marek