看了评测，G80开AA下降的幅度比R580大，原因？ - POPPUR爱换

原帖由 xreal 于 2006-11-9 17:43 发表
:huh: aa是要显存带宽来保证的。

原帖由 ayanamei 于 2006-11-9 17:44 发表

原帖由 linwu1 于 2006-11-9 17:35 发表
G80在多数游戏中开AA下降的幅度的比R580大，这样的水准，对抗R600估计有难度。

以tomshardware的FEAR为例,2560下

GTX 0AA 75    4AA    33
GTS 0AA 58    4AA    17
XTX 0AA    ...

原帖由 来不及思考 于 2006-11-9 20:56 发表
TGH,一个连NF680I 都不能第一时间拿到的网站,还是原来那个THG吗?
居然用FX60来测,真搞笑,国外的测试你还能看到几个用FX60的?

要比HD分辨率,一向偏A的anandtech这次测试只测了HD分辨率,只有2560*1600一个分 ...

原帖由 来不及思考 于 2006-11-9 23:51 发表
楼上，请你首先搞清楚

8800GTX和GTS虽然实际运算能力要大大超过X1950XTX，GTX可以达到近2倍的领先

但显存带宽并没有翻倍
GTX相比X1900XTX仅仅增加了50%不到，GTS更加少

而对于游戏测试来说，在非极限 ...

原帖由 来不及思考 于 2006-11-10 00:00 发表

老大，你们都不算频率的么

GDDR4最高可以到2.8GHz !!! :blink:

原帖由 来不及思考 于 2006-11-10 00:09 发表

纯粹比AA比带宽的时代，已经过了
以后是FP HDR with AA
Alpha AA with FSAA
Softshadow with AA的时代

G80虽然纯粹的带宽没有提升多少，但在FP Tex filter,ROP和正交Framebuffer上的重大变化足以在 ...

the standard X1950 XTX card falls back into the 2xAA mode even when 4xAA is requested and set in the game.

Whether or not this was an accidental bug or something else, there are probably numerous reviews online about the X1950 XTX cards that need to be re-evaluated

To answer some questions that have come up, the driver version I used to get the numbers above was Catalyst 6.10, default settings in the control panel. I have tested 6.9 and 6.8 and saw the same issue on these three games using the original X1900 XTX and X1900 CrossFire Edition cards as well

ATI Responds to OpenGL Performance Bug
Nov 7, 2006 at 03:49 PM by Ratchet14 Comments
ATI has responded to the high-resolution OpenGL performance issues on Radeon graphics cards reported by PCPer last week:
Hi all,

As highlighted on page 27 of the GeForce 8800 reviewers guide, and reported on last week by PC Perspective, I wanted to provide everyone with an update on the topic of ATI Radeon X1900 XT, X1900 XTX, and X1950 XTX cards dropping to 2xAA when 4xAA is set at 25x16 in OpenGL games.

The driver team has been exploring this topic over the weekend and has discovered that there is a bug in the memory allocation for the X1900 XT and XTX and X1950 XTX that is not affecting the CrossFire Edition cards. The slave cards currently allocate memory for two monitors (i.e. dual display). The CrossFire Edition cards only allocate memory for one monitor. The bug in our driver is such that the total memory allocated is based on the CrossFire Edition (master) cards and thus higher AA resolution settings fail for slave cards and the driver brings the application to a lower AA level.

For background on the topic of memory allocation, driver teams at both AMD and our competitor have several options they’re presented with when a card runs out of memory in a given application. They can choose to use system memory rather than the on-board memory buffer and accept low frame rates, they can choose to have the driver drop to a lower AA setting to maintain playable frame rates, or they can choose to not run the application at all (i.e. the driver closes the application and provides an error dialogue box).

In essence, the second option is what you’re seeing with the slave cards today, although as demonstrated by the CrossFire Edition cards, there is sufficient memory to run at 25x16 4xAA and the AMD driver team is working on that fix. Another example of this, is looking at the X1900 XT 256MB card at 25x16 4xAA in “Call of Duty 2” vs. a competing 7900 GT. At this setting, the 7900 GT provides a video memory error and doesn’t allow the app to run.

Regarding the ATI slave card memory allocation error, we have identified the code in our driver that causes this bug and will be fixing this in an upcoming Catalyst release.

Thanks,
Will Willis
Senior PR Manager
Advanced Micro Devices