Hi, I experience stuttering video playback in remote-viewer despite connecting via GBit/s LAN, using fast hardware and the QXL driver. Up until a video size of roughly 800x600 the playback is smooth. But on anything bigger, like my native resolution of 2540x1440, video playback is stuttering annoyingly. After lots of unsuccessful tinkering with spice parameters and qxl parameters I'm asking you guys for help. Client: Windows 10 1909 Remote Viewer 8.0-256 Quadcore i7-7820HQ 2.9GHz 16GB DDR4 RAM Host of the VM: Gentoo Linux Kernel 4.14.172 Qemu 4.2.0 Quadcore i7-7700K 4.2GHz 64GB DDR4 RAM Server is headless, has no dedicated graphics card, only the Intel HD 630 from the CPU Guest VM: Debian Bullseye I don't think it's guest related, because the same problem happens with a Windows 10 Guest with latest QXL drivers and spice-tools installed. Network performance client<=>host: Ping 0.2ms Throughput benchmarked at 960MBit/s Qemu invocation on host: #qemu-system-x86_64 -spice port=5906,addr=10.42.2.250,password=changed -vga none -device qxl-vga,ram_size_mb=128,vgamem_mb=32,vram_size_mb=128,vram64_size_mb=256,max_outputs=1 -M q35 -smp 2 -cpu host --enable-kvm -drive file=vmfllin.raw,if=virtio,format=raw,index=0,cache=none,aio=native -m 24576 -net nic,model=virtio,macaddr=52:54:00:74:01:06 -net tap,ifname=vmfllin,script=no,downscript=no -k de -monitor tcp:127.0.0.1:5956,server,nowait -device virtio-serial,id=virtio-serial1 -chardev spicevmc,id=vdagent,debug=0,name=vdagent -device virtserialport,bus=virtio-serial1.0,chardev=vdagent,name=com.redhat.spice.0 -rtc base=utc,clock=host -daemonize --device virtio-balloon -boot c -nodefaults -soundhw hda Spice parameters I tried: -spice streaming-video=all,image-compression=off,jpeg-wan-compression=never,zlib-glz-wan-compression=never,playback-compression=off -spice streaming-video=off,image-compression=off,jpeg-wan-compression=never,zlib-glz-wan-compression=never,playback-compression=off Guest kernel: Linux guest 5.4.0-4-amd64 #1 SMP Debian 5.4.19-1 (2020-02-13) x86_64 GNU/Linux guest kernel: qxl 0000:00:03.0: remove_conflicting_pci_framebuffers: bar 0: 0xe8000000 -> 0xefffffff guest kernel: qxl 0000:00:03.0: remove_conflicting_pci_framebuffers: bar 1: 0xf0000000 -> 0xf7ffffff guest kernel: qxl 0000:00:03.0: remove_conflicting_pci_framebuffers: bar 2: 0xf8054000 -> 0xf8055fff guest kernel: qxl 0000:00:03.0: remove_conflicting_pci_framebuffers: bar 4: 0xd0000000 -> 0xdfffffff guest kernel: qxl 0000:00:03.0: vgaarb: deactivate vga console guest kernel: [drm] Device Version 0.0 guest kernel: [drm] Compression level 0 log level 0 guest kernel: [drm] 24574 io pages at offset 0x2000000 guest kernel: [drm] 33554432 byte draw area at offset 0x0 guest kernel: [drm] RAM header offset: 0x7ffe000 guest kernel: [drm] qxl: 32M of VRAM memory size guest kernel: [drm] qxl: 127M of IO pages memory ready (VRAM domain) guest kernel: [drm] qxl: 256M of Surface memory size guest kernel: [drm] slot 0 (main): base 0xe8000000, size 0x07ffe000, gpu_offset 0x20000000000 guest kernel: [drm] slot 1 (surfaces): base 0xd0000000, size 0x10000000, gpu_offset 0x30000000000 guest kernel: [drm] Initialized qxl 0.1.0 20120117 for 0000:00:03.0 on minor 0 guest kernel: fbcon: qxldrmfb (fb0) is primary device guest kernel: qxl 0000:00:03.0: fb0: qxldrmfb frame buffer device Guest X-Org: X.Org X Server 1.20.8 [ 205.516] (II) LoadModule: "qxl" [ 205.516] (II) Loading /usr/lib/xorg/modules/drivers/qxl_drv.so [ 205.518] (II) Module qxl: vendor="X.Org Foundation" [ 205.520] (II) qxl: Driver for QXL virtual graphics: QXL 1 [ 205.525] (II) qxl(0): Creating default Display subsection in Screen section [ 205.525] (==) qxl(0): Depth 24, (--) framebuffer bpp 32 [ 205.525] (==) qxl(0): RGB weight 888 [ 205.525] (==) qxl(0): Default visual is TrueColor [ 205.525] (==) qxl(0): Using gamma correction (1.0, 1.0, 1.0) [ 205.525] (II) qxl(0): Deferred Frames: Disabled [ 205.525] (II) qxl(0): Offscreen Surfaces: Enabled [ 205.525] (II) qxl(0): Image Cache: Enabled [ 205.525] (II) qxl(0): Fallback Cache: Enabled [ 205.525] (==) qxl(0): DPI set to (96, 96) # glxgears 9709 frames in 5.0 seconds = 1941.675 FPS 11719 frames in 5.0 seconds = 2343.780 FPS Remote-Viewer console output on Windows client: "C:\Program Files\VirtViewer v8.0-256\bin\remote-viewer.exe" --hotkeys=toggle-fullscreen=shift+f11 spice://10.42.2.250:5906 (remote-viewer.exe:16324): GSpice-CRITICAL **: 08:00:32.467: _usbdk_hider_update: assertion 'priv->usbdk_api != NULL' failed (remote-viewer.exe:16324): GSpice-CRITICAL **: 08:00:32.526: file ../../src/usb-device-manager.c: line 1815 (probe_isochronous_endpoint): should not be reached (remote-viewer.exe:16324): Gtk-WARNING **: 08:00:32.950: Theme directory 256x256@2/animations of theme hicolor has no size field (remote-viewer.exe:16324): Spice-WARNING **: 08:00:50.804: ../../src/channel-display-gst.c:715:gstvideo_has_codec: No video decoders from GStreamer were found (remote-viewer.exe:16324): GSpice-CRITICAL **: 08:00:50.912: _usbdk_hider_update: assertion 'priv->usbdk_api != NULL' failed (remote-viewer.exe:16324): GSpice-WARNING **: 08:00:50.919: Warning no automount-inhibiting implementation available Thanks, Felix _______________________________________________ Spice-devel mailing list Spice-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/spice-devel