Higher clock speeds or higher on-board mem?

[Swi1ch]

So my plan for my rig is almost complete and it's down to choosing a Graphics card. I am looking currently at the 9800GTX+, but also the possibility of the 4870.

What I do want to know is whether I should aim for clock speeds or higher on-board memory when choosing a card (ATI or Nvidia) Particularly as there isn't a 9800GTX+ with 1gb onboard (On OC anyhow)

For example:

BFG GeForce 9800 GTX+ OC 512MB GDDR3 760MHz Core, 1890MHz Shader, 512MB 2250MHz GDDR3 Memory, 128 Stream Processors

VS.

Asus GeForce 9800 GT HybridPower 1024MB GDDR3 600MHz Core, 1024MB 1800MHz GDDR3 Memory, 112 Stream Processors

The BFG has way higher clock speeds, but will the double onboard memory of the Asus give it the upper hand?

Same with the ATI cards, would

Sapphire ATI Radeon HD 4850 1024MB 625MHz Core, 1024MB 1986MHz GDDR3 Memory, 800 Stream Processors

match

Asus ATI Radeon HD 4870 512MB "Dark Knight" GDDR5 750MHz Core, 512MB 3600MHz GDDR5 Memory, 800 Stream Processors

Or is it just a trade up?

 

[Monkeynut]

4850 is faster than a 9800GTX+ and a 9800GT. A 9800GT is a rebadged 8800GT.

 

[Rroff]

You can't compare clock speeds of cards unless they are the exact same model...

 

[RaV]

The GTX+ is a lot better that that 9800GT. For both the Nvidia and ATI cards in your list dont compare them just on ram sizes. The cards youve listed with the least ram are the fastest out of those.

4870 > 4850 >= 9800GTX+ > 9800GT

depending on your res, the cheapest 4870 would be your best bet if you can afford it. is the "dark knight" more expensive that the normal 4870's?

 

[Peter450]

Dark knight is about £150 i think including the vat, i guess it's a bit less now vat has gone down