Question about the cost factor of 128 Bit vs 256 Bit on graphic cards memory

Hi there, I'm new and i'm from germany, so please don't mind if my writing is a little
strange and please correct me if I make any mistakes So here goes:

I know its not really oc related, but if you don't know, then who does?
In a german forum We have a discussion going on about the cost factor of double
mem bandwith nearly doubling the cost off the graphics card alltogether. Is this true?

E.g. the 7600GT only costs half of the 7900GT mainly because of 128 to 256 Bit.

In my opinion, the main cost factor is the GPU/PS/VS and such and because of this I
don't think that a part of the GPU to RAM connection can be such an expensive part.

Do you know anything about it and can you tell me what parts make a gpu expensive
or cheap or tell me where i can look it up?

Thx a lot in advance! Greetings, Bo

One of the major reasons that the 7600 GT was able to debut at half the price of a MSRP 7900 GT is because it was pin compatible with the older 6600 GT PCBs if I recall correctly, which means though that you have the limited number of places to put the RAM modules for the bit width.

I don't think including the extra traces for a wider memory bus in itself adds significantly to a card's cost, unless manufacturers can get away with overall simpler manufacturing techniques for those PCBs like using a 4-layer PCB instead of a 6-layer one. Of course I don't know if the cards you cited both use the same number of PCB layers and if they can get away with a less expensive process for the 7600 it may or may not be determined by the memory interface. Laying out a 'reference' PCB is probably involves little cost because there's no design involved and it's not like they haven't mastered PCB manufacturing yet.

There are many other factors including memory type/speed used, the GPU itself costing more, larger size and other extra components on the 7900GT and finally market segmentation. It's very possible that the absolute profit margin is greater for the 7900GT.

And welcome to the forums

Just wanted to add, that when you buy a graphics card, get one with a 256-bit memory interface... it is worth every penny, and will "future-proof" your PC longer.
When newer games come out, the always need more graphics power.. for example... you have 2 identical machines, one with a Radeon 9500 Pro (128 bit) and one with a 9800 Pro (256)... theres still a few people around here still playing today's games with 9800 Pro's... hence 256-bit lets it handle more... same thing can be said with the GeForce FX 5700 Ultra and the 5900XT... these cards actually were around the same cost... but the 5900XT had 256bit memory... only one of these cards can handle F.E.A.R., Call of Duty 2, etc... Just my 2 cents... if you are considering a 7600GT.... take a look at the new 7900GS... it has 256-bit memory, and is quite a bit cheaper (almost $100 US) than the 7900GT, and performs almost identically.

I agree with Daredevil. Go with a 256 bit card. He's exactly right in that it will "future proof" your PC.

Take a look at this Toms Hardware Guide 3-part article. Somewhere in there they explain all that jazz.

Graphics Beginners' Guide part 1
Graphics Beginners' Guide part 2
Graphics Beginners' Guide part 3

Now, don't get insulted that it's a beginners guide. It has a lot of interesting points to consider when choosing a video card.

EDIT: Oh yes and by the way, welcome! Any question is welcome here, even if it's not OC related. Just as long as you put it in the right section.

lol people he's not asking anything about advice on a video card

As for '256>128 always'...performance is what matters not an architectural detail. It's like saying P4s are better than A64s because they have more MHz or cache. Obviously a higher prodcut in the same lineup is going to be better though that's pretty much a no-brainer