GTX 560 Ti 1Go or GTX 560 2 Go?

[danielj]

The price is similar.Even GTX 470/570 1.25 Go is too expensive for me.So in Celestia,is better to have more video memory or raw power?Or we can?t tell the difference?

[selden]

You need more graphics memory if you need to have many large Addons loaded simultaneously.

According to the benchmarks I've read just now, I expect that Celestia would report only a small difference in fps between those two models, too small to notice yourself if you didn't look at that number.

Note that the "GTX 560 Ti" is not the same model as the "GTX 560 Ti 448 Cores". The latter won't be available for another week or so, and probably would be noticeably faster.

[danielj]

I think this possibility is out of the question.The NEW 560 Ti is almost a 570 and will probably be almost as expensive as it.

[danielj]

Well,I think my next video card will be a Geforce GTX 560 Ti 2 Go.Unfourtanetelly,I couldn?t afford the 448 cores.

[danielj]

Well,my new system will have 8 GB of main RAM and 2 GB of VRAM.I think will be more than enough to run Celestia with the highest texture resolution and models.People with 6 GB of RAM or more,does it affect Celestia frame rate?

[John Van Vliet]

--- edit ---

[danielj]

If I lock the refresh rate to 60 fps,what happens of some scene become lower than 60 fps.Does it have tearing?
I will have a Corei7 2600,8 GB RAM and a GTX 560Ti.
One of the best computers some time ago was CAP-Team.Which is the best computer today?

[selden]

When "vertical sync" is enabled, screen updates are always synchronized to the screen refresh rate. The display buffer is updated only during the "vertical retrace interval" when no image is being shown on the screen. There is no visible tearing. (I put "vertical retrace interval" in quotes because that name only applies to CRT displays, although the same time delay is built into the video signal used for flat-panel displays.)

Tearing happens when the graphics output is changed while the image on the screen is being redrawn.

[danielj]

Yes,but suppose I have frame rate as low as 15-20 fps in some kind of model.When I syncronize to 60 Hz,what is going to happen in these models,in visual terms?

[selden]

You aren't "synchronizing to 60 Hz." The graphics driver option is "vertical sync". In other words, the visible "on screen" display is changed synchronously with the time when the on-screen display has finished being drawn.

More specifically, the graphics hardware has several video buffers. The program (e.g. Celestia) draws its pictures into one of the video buffers (call it buffer #2) while values are being read out of another buffer (call it buffer #1) to draw what you see on the screen. Then, during the "vertical retrace interval", when the on-screen display has finished being updated, the graphics hardware changes the buffer pointer. The next on-screen image is drawn from buffer #2, and the application program (e.g. Celestia) starts drawing into buffer #1. If "vertical sync" is not enabled, then the buffer pointer is changed whenever the program finishes drawing.