4

While searching for ways to increase responsiveness of xrdp, I noticed a lot of recommendations for setting max_bpp=128 in xrdp.ini.

Why would setting the max bits per pixel to 128 make a difference? Does it make memory reads and writes noticeably faster? It seems like sending more data would increase overhead. Additionally, man pages for xorg.conf state that hardware is only going to use 24 bits.

damn_dirty_ape
  • 41
  • 1
  • 3
  • Using Windows 10 RDP on my remote host, it doesn't seem to make a difference since 32 bit is the highest it allows. – iyrin Dec 08 '19 at 16:42

1 Answers1

4

Maximum supported bpp at the moment is 32. The only way max_bpp=128 can be made sense of is by looking at xrdp source code: setting server's max_bpp at 128 makes the value ignored by putting it at a level well above any potential client's bpp (bit per pixel).

    if (self->rdp_layer->client_info.bpp >
            self->rdp_layer->client_info.max_bpp)
    {
        LOG(LOG_LEVEL_WARNING, "Client requested %d bpp color depth, "
            "but the server configuration is limited to %d bpp. "
            "Downgrading the color depth to %d bits-per-pixel." 
   ...

Therefore max_bpp=128 is as good as max_bpp=32 and also not setting max_bpp in the xrdp.ini at all. The client controls the color depth and the associated network bandwidth under any such scenario.

P.S. I'd be thrilled to hear facts to the contrary from the author of an answer to xrdp and xfce4 Ubuntu > 18.04 Unusable

Serge Pavlov
  • 141