Are you using 2, USB ports or running both through an adapter so you need to use only 1 USB port on the laptop?
I'll add one or two 19" regular LCDs to my two existing 19" ones. They run 1280x1024. I have no plan to go to widescreen until the old ones die. I'll go with DVI first, but can live with VGA. The nVidia NVS 440 would cost $250 or more. I'll wait for a later time. I'm short on PCI video card anyway. If later on, I'll need to add more monitors through another computer, I can still use this, instead of going through this again. Thanks.
You should be just fine with 1280x1024 on DVI. Most have already switched to widescreen already. By still using conventional 19", the NVS 440 wouldn't benefit you.
I read quite a bit discussion here about large widescreen LCDs. I do not know how people manage the 30" LCDs. The widescreen is going to be inevitable, but will be a hard transition to me. I've been using 19" regular for many years, and happy with 3-4 regulars at work. I trade mostly energy, so I need 3-4 intra-day and 3-4 daily charts. Then one section for news and one or two section for quotes. The main screen is for trading, email, TV, etc. Right now, I divide each screen into 4 sections. 19" is just perfect for my needs. If I move up to widescreen, I think I'll just need 3 24"/25" LCDs. Then I'll have to divide the screen into 6 sections each. 4 sections are too wide, particularly for quotes. But I've not tried yet. Also, I do not want to run out of desk space. My desk is just like a regular trading desk. 4 19" is the max.
Got the Matrox G450 MMS card. I disconnected the fan since it is loud and there is decent airflow in the case. It suits my need perfectly. With the Win7 upgrade, I may be able to use both ATI PCIe and Matrox G450 in the same machine, to drive 6 monitors or more. Quad video card is a good options to have.
I'd be curious about that compatibility myself, since those 2 brands rarely get along in the same machine. Matrox & nVidia, yes, but Matrox & ATI is usually a no-go.
I do not know yet. Win7 claims support for multiple video cards from different vendors. I have no needs right now. I'll try when I get some spare time...
The question in the headline is whether PCIe slots are backwards compatible or vice versa. The way I understand it (and you can check wikipedia if you want) is that all sucessive generations of PCI interface is backwards compatible with all previous generations meaning you should be able to run anything that fits. Your bandwidth will be limited to the lesser of all involved as with any computer system/ component interface.