Unless your existing machine has failed or you'll be tossing it such that you need to use the new one immediately or won't have any backup, skip the onboard.

I think you have your answer in the first part of your question. 

Not sure though about the different drivers part.   Someone with expeience witll come along and proved that answer,

At the very minimum, AFAIK Aero on Vista/7 won't work if you have both ATI and nVidia drivers loaded simultaneously.

Even if one or the other is disabled? Good to know. I may go with no onboard and probably keep a very low end video card around (just something to connect the monitor to) in case the good one fails for what ever reason. Thank you.

The chances of one failing is pretty slim. If your going to buy a Nvidia card buy one with a lifetime warranty from a company like EVGA.

I'll keep that in mind but if it did, which i have read happenes (it's just dead on arrival or it's damaged and eventualluy breaks), I just want to be sure I can still use the computer while I wait for a replacement.

Call it a coincidence... but, the 8600GS overheated two weeks ago and was swiftly replaced (under warrenty & including service) by a decent 9600GT (both 512MBs) & lucky me, that Acer Tower Mobo had a resident 7100 (941-GPU, IIRC) chipset integrated so i could actually loadup Vista & still use the PC on the VGA array even with such a temporary solution & verify system integrity. Now, it's back to pure DVI and -- speedy performance.

No reasonably good Mobo should be without one! Just in case.

I'd say go with onboard video. The BIOS for the motherboard almost always allows you the option to disable the onboard if you are using an aftermarket video card. This way Windows never knows the onboard video exists, so you won't have driver issues. At any time you can just enable onboard video again if you need to.

On the other hand, I'm not sure what price range or quality of mobo you are looking for, but high end mobos tend to come without onboard video. If low end is where you're at, onboard is more common as a feature.

Why pay for something you probably will never use (on-board graphics)? Besides on-board typically shares your RAM. Better to have the dedicated memory on the video card.

I've always gone with mobos without on-board graphics... having upgraded once or twice, I have a couple of spares for if/when my main card fails.  Having said that, (touch wood) I've never had a card fail. 

If you ensure proper installation, adequate cooling and keep your drivers up to date, it's not likely you'll experience a GPU failure... it's rare, though keeping a spare (affordable and low-end will do) is a good idea, just in case.

And this....

... a dedicated graphics card with its own memory performs better and does not drain system resources anywhere near as much. The imporatant thing, however, is to ensure your power suppy is more than capable... putting a higher-end graphics card with an under-powered PSU can fry your entire system.

I also have a couple of spare vga cards on hand, but the only failure I have had in the last 5 years on video cards is from the FANS on them jamming.

harpo

some of us use multi-GPU systems. *cough*SLI*cough* so the chances of having NO video are very low. i've never bought onboard, and have a disdain for it. besides, unless your old computer is being trashed ASAP, or it uses an onboard video/PCI/AGP card, you could just borrow the video card from your old computer while waiting.

This problem is fixed in Windows 7. You can use Nvidia and ATI together now.

In general on-board video is much much slower than discrete video, even when the chips of the on-board are of the same generatio as the discrete. In addition there is either shared memroy with system RAM or a much smaller than usual amount of dedicated memroy.

If you are build a system to use as an entertainment device on-baord works well as long as you don't intend on gaming. On-baord ATi video has a much faster DVD decoding since it is integrated into the chips directly. I don't know about the latest generation of Nvidia but over the last several years ATI has been faster at this.

Again if you want to game on-board of either variety will leave you disappointed.

With as much memory as we see people using these days having onboard video really does not hurt system performance.

kona,

UNLESS the onboard video has it's OWN ram, IT DOES IMPACT the speed of access to the ram as the video circuitry needs continous access to the ram as does the CPU, so there is contention for access to ram(which by the way is often significantly slower than the CPU) and as onboard video is given priority by the mobo makers the CPU HAS TO WAIT for the video to release ram access.

I have confirmed this pattern by observation in several instances of budget systems operating slower than the CPU/ram specs suggest, then adding a basic video card eg for agp mobo's a geforce 5200, for pciexpress mobo's a geforce 7300, and noticing a near doubling of system boot speed WITH the same ram/cpu/mobo, just added a video card.

harpo