Strongest card compatible for an old PCI express x16 1.1 slot

[vhn1]

Hi, I've been wanting to upgrade from my current set up to better handle games like bf3/bf4 (medium-high settings). I do not have the money to buy a new gaming computer, so I would like a new GPU instead (maybe power supply too?). However, I want to maximize the use of all the parts yet avoid any cards that surpass my specs. If I'm not mistaken, newer PCI-e 3.0 cards would simply be a waste and possibly incompatible with my current 1.1 slot? I would prefer a card cost of <$140.

Here are my system specs:
-HP NC692AA-ABA m9510f motherboard
-2.33GHz Intel Core 2 Quad Processor Q8200
-2x 4GB 800MHz DDR2 SDRAM
-NVIDIA 240GT 1GB
-350W PSU
-Monitor is 1280x1024

Also, I would like to know how to determine the bandwidths of my slot and other cards that I may be considering. According to TechPowerUp GPU-Z, my current GPU has 28.8 GB/s bandwidth, but I can't seem to identify the bandwidth for my slot.

 

[leo2kp]

First, you'll want a new PSU. Second, PCI-E 3.0 cards are compatible with 1.1 slots, but there will be a performance hit. The 28.8 GB/s is memory bandwidth. That is different than the interface bandwidth between the card and the rest of the PC. I think a GTX 760 would be more than enough for your rig and wouldn't require a massive PSU. 500-ish watts should do it.

 

[vhn1]

First, you'll want a new PSU. Second, PCI-E 3.0 cards are compatible with 1.1 slots, but there will be a performance hit. The 28.8 GB/s is memory bandwidth. That is different than the interface bandwidth between the card and the rest of the PC. I think a GTX 760 would be more than enough for your rig and wouldn't require a massive PSU. 500-ish watts should do it.

Ah, so is there a way to determine my PC's interface bandwidth, assuming that is what matters more here? I spotted some excellent deals for AMD 7850 and 7950. Would these be overkill for my PC?

 

[a1blaster]

buy the strongest gpu you can afford today...nevermind the bottleneck...upgrade your cpu/mobo later

 

[coozie7]

The GT240 is about halfway down, on the left: http://www.tomshardware.co.uk/gaming-graphics-card-review,review-32803-7.html
Anything 3 tiers over it is considered a reasonable upgrade.
With a PCI-E 1.1 motherboard I'd go Nvidia, there have been a FEW problems with AMD PCI-E 3.0 cards with this particular slot revision.
The HD7870 and 7950 are PCI-E 3.0 cards so I'll not wholeheartedly recommend them for that reason. I'll also not recommend them because they are total, cluster-thermonuclear overkill for a 1280x1024 monitor.
Probably the best value for you would be a GTX650Ti with the faster GTX650Ti Boost being my top pick, anything higher is really going to be wasted on such a low resolution.