The monitor setup I've had with my XFX Radeon HD 5850 has been one DVI monitor as my main and one HDMI monitor on my right. I had been planning on getting a second DVI monitor down the road as I was aware the HD 5000 series supports 3 monitors on one card. Well, today I acquired an older Samsung monitor that only has VGA . I figured "Hey, I got a VGA->DVI adapter ill just plug this baby in!" Well, that didn't work.
I have since learned that:
A) In order to use a 3rd monitor on an HD5850 you must have one of those three outputs through the displayport on the GPU. (Which honestly I didn't realize it had until now, I've never used one) and...
B) If using a displayport adapter, it must be an ACTIVE adapter, meaning it has a chip in it that sets the clock properly for the 3rd monitor which is required to be in sync with the other two as the card can only properly clock two displays on it's own.
So, to get to my question....
I am going to buy an Active displayport adapter, BUT, could I use a DVI-> Displayport adapter (to change the clock) and then a VGA->DVI passive adapter in that to go to my older Samsung monitor. The reason being. I do not plan on using this monitor forever, just untill I can afford a second DVI display. Once I go to replace the VGA monitor I could just take the passive VGA->DVI adapter off and plug straight into the Active DVI->Displayport, and not have to buy a whole new Active adapter which run about 26 bucks. Not expensive by any means, but I don't want to have to buy two if I don't need to. Get me?
(I know this post is long but I felt it was important to illustrate the issue as many seem to be oblivious to it.)
DVI/Display port adapters are DVI-D. DVI-D is digital. there is no analog signal so a VGA adapter will not work. Instead, hook the VGA monitor up to the DVI-I port on your card that your current DVI monitor is using using the DVI-I to VGA adapter, then hook your DVI monitor up to the display port to DVI-D adapter.