显卡是A卡，驱动是官方驱动。在windows下玩dota2爽的很，为什么在ubuntu14.04steam下就卡的不行？求大神解读。而且，steam好像不能识别我的显卡，很奇怪。

A 卡閉源驅動 常常跟 Linux-kernel 版本 捆綁
所以 Linux-kernel 升級 可能就會影響到 A 卡閉源驅動是否相容勝任

把下面指令 複製 貼進終端機 執行
1. uname -r
2. sudo lspci -knn
3. sudo lshw -numeric -class video
4. sudo ubuntu-drivers devices
把結果直接 選取/複製 貼上來
不必擷圖

我把官网驱动卸载了，没想到反而不卡了。
看到大神很激动，现在应该是ubuntu14.04默认驱动：
siriusy@siriusy-PC:~$ uname -r
3.13.0-53-generic
siriusy@siriusy-PC:~$ sudo lspci -knn
[sudo] password for siriusy:
00:00.0 Host bridge [0600]: Intel Corporation Xeon E3-1200 v3 Processor DRAM Controller [8086:0c08] (rev 06)
Subsystem: Gigabyte Technology Co., Ltd Device [1458:5000]
00:01.0 PCI bridge [0604]: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor PCI Express x16 Controller [8086:0c01] (rev 06)
Kernel driver in use: pcieport
00:14.0 USB controller [0c03]: Intel Corporation Device [8086:8cb1]
Subsystem: Gigabyte Technology Co., Ltd Device [1458:5007]
Kernel driver in use: xhci_hcd
00:16.0 Communication controller [0780]: Intel Corporation Device [8086:8cba]
Subsystem: Gigabyte Technology Co., Ltd Device [1458:1c3a]
Kernel driver in use: mei_me
00:19.0 Ethernet controller [0200]: Intel Corporation Ethernet Connection I217-V [8086:153b]
Subsystem: Gigabyte Technology Co., Ltd Device [1458:e000]
Kernel driver in use: e1000e
00:1a.0 USB controller [0c03]: Intel Corporation Device [8086:8cad]
Subsystem: Gigabyte Technology Co., Ltd Device [1458:5006]
Kernel driver in use: ehci-pci
00:1b.0 Audio device [0403]: Intel Corporation Device [8086:8ca0]
Subsystem: Gigabyte Technology Co., Ltd Device [1458:a182]
Kernel driver in use: snd_hda_intel
00:1c.0 PCI bridge [0604]: Intel Corporation Device [8086:8c90] (rev d0)
Kernel driver in use: pcieport
00:1c.3 PCI bridge [0604]: Intel Corporation Device [8086:8c96] (rev d0)
Kernel driver in use: pcieport
00:1d.0 USB controller [0c03]: Intel Corporation Device [8086:8ca6]
Subsystem: Gigabyte Technology Co., Ltd Device [1458:5006]
Kernel driver in use: ehci-pci
00:1f.0 ISA bridge [0601]: Intel Corporation Device [8086:8cc6]
Subsystem: Gigabyte Technology Co., Ltd Device [1458:5001]
00:1f.2 SATA controller [0106]: Intel Corporation Device [8086:8c82]
Subsystem: Gigabyte Technology Co., Ltd Device [1458:b005]
Kernel driver in use: ahci
00:1f.3 SMBus [0c05]: Intel Corporation Device [8086:8ca2]
Subsystem: Gigabyte Technology Co., Ltd Device [1458:5001]
01:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Pitcairn PRO [Radeon HD 7850] [1002:6819]
Subsystem: PC Partner Limited / Sapphire Technology Radeon HD 7850 2GB GDDR5 DVI-I/DVI-D/HDMI/DP [174b:e221]
Kernel driver in use: radeon
01:00.1 Audio device [0403]: Advanced Micro Devices, Inc. [AMD/ATI] Cape Verde/Pitcairn HDMI Audio [Radeon HD 7700/7800 Series] [1002:aab0]
Subsystem: PC Partner Limited / Sapphire Technology Device [174b:aab0]
Kernel driver in use: snd_hda_intel
03:00.0 PCI bridge [0604]: Intel Corporation 82801 PCI Bridge [8086:244e] (rev 41)
siriusy@siriusy-PC:~$ sudo lshw -numeric -class video
*-display
description: VGA compatible controller
product: Pitcairn PRO [Radeon HD 7850] [1002:6819]
vendor: Advanced Micro Devices, Inc. [AMD/ATI] [1002]
physical id: 0
bus info: pci@0000:01:00.0
version: 00
width: 64 bits
clock: 33MHz
capabilities: pm pciexpress msi vga_controller bus_master cap_list rom
configuration: driver=radeon latency=0
resources: irq:50 memory:e0000000-efffffff memory:f7e00000-f7e3ffff ioport:e000(size=256) memory:f7e40000-f7e5ffff
siriusy@siriusy-PC:~$ sudo ubuntu-drivers devices
== /sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0 ==
model : Sapphire Radeon HD 7850 2 GB GDDR5 DVI-I/DVI-D/HDMI/DP
vendor : Advanced Micro Devices, Inc. [AMD/ATI]
modalias : pci:v00001002d00006819sv0000174Bsd0000E221bc03sc00i00
driver : xserver-xorg-video-ati - distro free builtin recommended
driver : fglrx - distro non-free
driver : fglrx-updates - distro non-free

1. 顯卡 AMD Radeon HD 7850

2. 目前作用中驅動 開源 radeon

3. https://help.ubuntu.com/community/Radeo ... _Supported
Fully Supported
All these Radeon(HD) cards and derivatives have good 3D acceleration support.
TAHITI/PITCAIRN/VERDE Radeon HD 7000/"Southern Islands" series
3-1. Pitcairn PRO [Radeon HD 7850] 在 開源 radeon 充分 3D 加速 支援名單內

3-2. 支援 HDMI_Audio
https://help.ubuntu.com/community/Radeo ... HDMI_Audio
3-3. 支援 Power Management
https://help.ubuntu.com/community/Radeo ... _and_Later

4. 閉源驅動 Catalyst 合適版本 (早期 Ubuntu 稱為 fglrx)
http://support.amd.com/en-us/download/d ... 20x86%2064
AMD Catalyst 14.12 Omega
4-1. http://support.amd.com/en-us/kb-article ... Notes.aspx
AMD Radeon HD 7000 Series 在 AMD Desktop Product Family Compatibility ​名單內
4-2. http://support.amd.com/en-us/kb-article ... Notes.aspx
Ubuntu 12.04.4 LTS, 14.04 LTS 在 支援名單內 # 注意 只有 12.04.4 及 14.04 沒有 其它 Ubuntu 版本 跟 Linux kernel 版本有關
4-3. 安裝方法 ... 直接從官網下載來安裝
viewtopic.php?f=42&t=467239&hilit=Omega+AMD
https://help.ubuntu.com/community/Binar ... 7s_website
http://support.amd.com/en-us/kb-article ... Notes.aspx

5. http://packages.ubuntu.com/search?suite ... chon=names
ubuntu 14.04 套件庫供應的版本還沒有 14.12 (14.501.1003)

6. 進階參閱
https://steamcommunity.com/app/221410/discussions/4/
Steam for Linux

非常感谢，我先不折腾了，慢慢跟大神们学习。

回头我也试试，我的内存10G，显卡有些喳喳