512 mb graphics card

[FroggyKid]

im trying to choose a 512mb card for my computer, but i dont understand the significance of:
RAMDAC
Memory Type
Core Clock
Memory Clock

i really dont care about the HDTV inputs, any suggestions? advice? information?

 

[borat_sagdiyev]

what graphics card slot do you have? pci, agp or pci-express?

 

[FroggyKid]

i have pci express, im building a new computer so im trying to stick to the best graphic port. i just dont understand the finer points of graphics cards.

 

[~mr mixx~]

< moved >

as the General Electricals sub forum is non-computer related threads.

 

[mayorredbeard]

RAMDAC:
http://en.wikipedia.org/wiki/RAMDAC

Memory Type (right now the two main types talked about are gddr3 and gddr4)
GDDR3: http://en.wikipedia.org/wiki/GDDR3
GDDR4: http://en.wikipedia.org/wiki/GDDR4

Core clock is basically how fast your graphics card processes information. If you want a real in depth explanation, of how it actually works, rather then this rudimentary explanation google has plenty of hits. more is better.

Memory clock refers to the clock speeds of the on board memory of the graphics card. more is better.

 

[ownage]

there is no GDDR4 right now. GDDR3 is the fastest you can get. There is more to video cards than the RAMDACS, clock speeds of core and memory, and type of memory. There is memory bus, pipelines, and bandwidth (it kind of ties in with memory bus). Now, on to memory bus.

Nvidia and ATi cards differ a lot. In ATi's new x1k series cards, it uses a ring bus. Xbitlabs has a very good explanation in how it works.

Ring buses go around the entire die and help to simplify and optimize its interconnects. The chip components can thus be connected in the shortest way. Coupled with the dispatch unit, this solution minimizes latencies and signal distortion at memory write operations. Thanks to the Ring Bus technology, the RADEON X1800/X1600 can work with high-frequency memory like GDDR4, for example, while a traditional architecture wouldn't support GDDR4 due to interference in the not optimally wired connectors inside the GPU.

The memory is connected to the buses at the so-called Ring Stops. There are four such stops in total; each has two 32-bit access channels. For comparison: the memory of the RADEON X850 connects to the controller through four 64-bit channels. Each Ring Stop can give out data to the requesting client, according to the memory controller's instructions.

The Ring Bus memory subsystem works simply. A client sends a data request to the memory controller which is located in the center of the chip. The memory controller uses a special algorithm to determine the priority of each request, giving the highest priority to those that affect the performance the most. Then it sends an appropriate request to the memory chips and sends the data along the Ring Bus to the Ring Stop nearest to the requesting client. From the Ring Stop the data arrives to the client. A so-called Write Crossbar Switch is located around the controller proper for optimal memory access – it makes sure the requests are distributed evenly.

The operation algorithm of the new controller can be programmed from the driver, so its operation can be improved further in the future. Moreover, ATI has a theoretical opportunity to program the controller for a specific application and create an appropriate profile in the Catalyst driver.

The cache has become fully associative, i.e. any cache line can store the contents of any location in the external memory.

The frequency being the same, an associative cache works more efficiently than a direct-mapped cache. Thus, the new architecture has a great performance reserve for applications critical about the graphics memory subsystem bandwidth. In other words, the RADEON X1000 is expected to perform well in high resolutions and/or with enabled full-screen antialiasing and anisotropic filtering.

The HyperZ technology has also been improved and a more sophisticated algorithm is now employed to identify invisible surfaces that are to be removed. ATI says the new algorithm is 50% more efficient than in the RADEON X850.

Note that although RADEON X1300 doesn't support Ring Bus as well as programmable memory requests arbiter, it uses other techniques intended to improve the memory bandwidth of the RADEON X1000 family.

Now with that said and done, the memory bandwidth on ATi cards is huge. Pair that up with 48 pixel processors and you have yourself a great video card. Now, what Nvidia has done is completely different. They use a traditional 256-bit bus, not a ring bus. But they have enable 24 pixel shader pipelines on their 7900GT(X) cards. That allows more pixels per second to fill onto your screen. This allows for the X1900XTX to compete with the 7900GTX and so forth. Hope this clears stuff up why ATi can keep up with Nvidia even though Nvidia has more pixel shaders. And keep in mind that ATi cards are already GDDR4 compliant

 

[Computer Head]

Nice Quote, ownage! This pretty well explained it.

 

[Gamingfreak]

i wouldnt get a 512mb card if i were u since direct x 10 comes out soon then that nice expensive card wont be all that good anymore

 

[joxley1990]

If you really want a 512MB card, hows the 7900 looking for you?