在Debian中的Radeon显卡设置

我是Debian Jessie的全新用户。我注意到所有视频都滞后于例如Vlc或Youtube。我意识到它可能是视频卡驱动程序的问题。我有Radeon R6 M340DX（双显卡）。这是输出lspci：

00:00.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1576
00:00.2 IOMMU: Advanced Micro Devices, Inc. [AMD] Device 1577
00:01.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Device 9874 (rev c5)
00:01.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Kabini HDMI/DP Audio
00:02.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 157b
00:02.2 PCI bridge: Advanced Micro Devices, Inc. [AMD] Device 157c
00:02.3 PCI bridge: Advanced Micro Devices, Inc. [AMD] Device 157c
00:03.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 157b
00:03.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Device 157c
00:08.0 Encryption controller: Advanced Micro Devices, Inc. [AMD] Device 1578
00:09.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 157d
00:09.2 Audio device: Advanced Micro Devices, Inc. [AMD] Device 157a
00:10.0 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB XHCI Controller (rev 20)
00:11.0 SATA controller: Advanced Micro Devices, Inc. [AMD] FCH SATA Controller [AHCI mode] (rev 49)
00:12.0 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB EHCI Controller (rev 49)
00:14.0 SMBus: Advanced Micro Devices, Inc. [AMD] FCH SMBus Controller (rev 4a)
00:14.3 ISA bridge: Advanced Micro Devices, Inc. [AMD] FCH LPC Bridge (rev 11)
00:18.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1570
00:18.1 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1571
00:18.2 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1572
00:18.3 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1573
00:18.4 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1574
00:18.5 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1575
01:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8723BE PCIe Wireless Network Adapter
02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 10)
03:00.0 Display controller: Advanced Micro Devices, Inc. [AMD/ATI] Sun XT [Radeon HD 8670A/8670M/8690M] (rev 83)

谢谢您的帮助！