All the USB-to-VGA (or DVI) adapters I bought 2 years ago only support the resolution up to 1680 x 1050. Diamond, IOGear and SIIG. I am in search of one of these adapters that would support the 1920 x 1080 configuration. Came to some real disappointments. Bought an IOGear GUC2020DW6 USB-to-DVI adapter. On the box, it clearly said the device supports the 1920 x 1080 resolution. But it doesn't. All I got was 1680 x 1050 max. Called their technical support line. Came to an argument that the rep insisted I need to update the video device driver on my laptop to the latest version (what does that got to do with the IOGear device???) and it would work. I did as they suggested. Same thing. Resolution only 1680 x 1050. When I questioned HOW to get that 1920 x 1080 resolution to work, they just couldn't answer it but said it was a problem with my video driver. What a bag of hot air. Bought another make "Aluratek " AUD200F USB-to-DVI adapter. Again, the box clearly labelled that it supports the resolution of 1920 x 1080. It doesn't. The driver disk that they provided is actually the DisplayLink software - which is used by IOGear. I think this is a Chinese firm reversed-engineered the IOGear hardware and sold under their own brand name, and didn't bother to write their own driver software. The problem is the same as IOGear's. Highest resolution 1680 x 1050. I tried Tritton UV200 USB-to-DVI adapter. $80. This one... to my pleasant surprise, does work. Resolution 1920 x 1080. I gathered that Diamond BVU195 should also support the 1920 x 1080 resolution. Haven't tried this one. But since I have found one that works, I probably won't.
That's some great info. Thanks What generates, and pushes the graphics bits to the display? Would it be possible to use multiple Tritton UV200 USB-to-DVI adapters to extend the laptop desktop across more than one display of a size and resolution you are using; additional to the laptop's? Does the laptop's graphics 'card' have much effect on the above? Does the CPU have much effect on the performance of multiple graphics displays?
RE: What generates, and pushes the graphics bits to the display? The driver software generates and pushes the graphics bits through the USB port to the adapter, which converts things into DVI signals. RE: Would it be possible to use multiple Tritton UV200 USB-to-DVI adapters to extend the laptop desktop across more than one display of a size and resolution you are using; additional to the laptop's? Yap. Per their document (I haven't tried it on Tritton but other similar adapters worked okay): Add up to six external video card's via available USB 2.0 ports for PC users. http://www.trittonusa.com/index.php/products/usb_video_technology/see2-xtreme-uv200/ RE: Does the laptop's graphics 'card' have much effect on the above? I don't think there is any effect at all. That's my point. It is going through the USB port and the adapter. RE: Does the CPU have much effect on the performance of multiple graphics displays? That I couldn't tell. My laptop has an i7 720QM processor. One USB graphics adapter. No performance impact noticed. One desktop has an i7 930 processor. 2 USB graphics adapters. No performance impact noticed. I suppose if the processor is older/slower (e.g. Pentium, C2D or something) it may be more noticeable.
Could one display each attach to 1 VGA (15-pin) and 1 HDMI laptop port for extended desktop use? where the native screen and the two addtl screens will display three different areas of the desktop?
These days a laptop is usually equipped with a second display port. Usually a VGA. Some: a VGA and a HDMI. However, you can only use either the VGA or the HDMI, not both at the same time, for your second display off your laptop. Then... when you add a USB-to-VGA (or USB-to-DVI) adapter, you can have a third monitor displaying the third area of your desktop. (If you have 2 USB-to-VGA adapters, you can display a fourth area of your desktop. Etc.)
Does laptop screen size have any effect on the size/ resolution of the external displays it can drive? Else equal, will a 17.3" screened laptop provide advantages driving external displays that a 14" will not?
It is not the laptop screen size that has an effect. It is the graphic chip your laptop vendor choce to use that determines what resolutions it can support. Though if you have a smaller screen laptop, they may use a chip that supports lesser resolutions. The laptop's built-in graphics chip is what drives your external monitor. Use this simple tool to check for yourself. On your laptop: Start... Type in "dxconfig" in the command box. That should bring up the DirectX Diagnostic Tool. Look at the "Display 1" tab. It should list your graphics chip type. Look up the specs and see what resolutions it can support. e.g. (enclosed)... mine (HP dv8t 1100 laptop)... HP uses NVidia GeForce GT 230M. And I looked up the specs online: http://www.nvidia.co.uk/object/product_geforce_gt_230m_uk.html
Or if you are considering buying a new laptop, check our their technical specs (particularly: what graphics chip they use) before buying.
When using a Tritton UV200 USB-to-DVI adapter: "Does laptop screen size have any effect on the size/ resolution of the external displays it can drive? Else equal, will a 17.3" screened laptop provide advantages driving external displays that a 14" will not?"
Oh, okay. If you use a USB-to-DVI adapter, your external monitor display is driven by the graphic chip and circuitry provided by that adapter. Your laptop's screen size is irrelevant. A UV200 can drive an external monitor with 1920 x 1080 resolution whether you use a 17.3" laptop or 14" laptop.