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Old 08-08-03, 08:29 AM   #83
volt
 
Join Date: Jul 2002
Location: /dev/null
Posts: 1,556
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I took some time off today to reconfigure my two systems and see what is causing the flickering.

Main System
Abit N7F-S 2.0
Barton 2800+ @ 2.3GHz (200x11.5)
TwinX 512MB Corsair 3200LLPT (dual-channel)
Prolink GeForce FX 5900
SLK-900U + 92mm Panaflo
WD 40GB HD
Chieftec Fulltower + 420W Chieftec PS
ViewSonic P95f+
Windows XP with SP1 + Detonator 44.03

Sub System
Asus A7N8X 2.0
AXP 1700+ JIHUB DLT3C @ 2.1GHz (200x10.5)
256MB Corsair 3200LL
NVIDIA GeForce FX 5600 Ultra
Alpha PAL8045U
250GB Storage
Vanilla Tower + QTec Goldplated 400W PS
ViewSonic P95f+
Windows XP with SP1 + Detonator 44.65

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The flickering has been first reported while 5900 was in the Main System. Let's look at that first:

1. I have swapped power supply cables from Sub System. They were different brand and more flexible
2. FX 5900 has been unplugged from external power
3. Monitor was connected through DVI->VGA adapter
3. The card has been underclocked to 300MHz core / 650MHz memory

Games tested: UT2003, C&C: Generals, Colin McRae 3, Hitman 2, Raven Shield. I have attached a UT2003 demo so you guys can check it out. This is the map that should be used to check out the flickering.

Status: flickering

To play the demo: Put flicker.dem into \System folder, Launch the game, enter console and type: demoplay flicker
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Then I have moved the 5900 into the Sub System.

1. Swapped the cables again
2. Powered off the 5900
3. Connected it through DVI->VGA
3. The card has been underclocked to 300MHz core / 650MHz memory

Same set of games was tested.

Status: flickering
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I have tested the FX 5600 in both systems with two types of cabling and found out that there was no flickering. What Mike mentioned was different. He has seen vertical bars moving from the bottom all the way to the top of the screen. I was very surprised to see a much cleaner screen when the 5600 was placed, even in 2D I could see a clear difference.

A similar swap has been made with a Ti4600 and neither of the systems produced any sort of flickering.

Conclusion:

1. Tested 3 different cards on 2 different systems.
2. Two sets of power cables were tested.
3. 5900 flickers in both systems, even with DVI->VGA adapter, unplugged power connector and downclocked card.
4. Ti4600 and 5600 do not produce flickering in either system.
5. There appears to be less flickering when lower resolutions are used: 1024x768 / 800x600
6. Flickering appears regardless of the API; DX or OGL
7. Flickering intensifies when there is more motion on the screen
8. Flickering does not disappear when the video card is underclocked and/or monitor is set to highest refresh rates and/or V-Sync is enabled
9. There is slight flickering going on while on desktop, barely visible but I can see it.
10. To see whether the card flickers in 2D, right click on desktop->properties->settings->advanced->GeForce FX 5900 Tab->Clock Frequencies->Click Auto Detect button. This will detect the appropriate clocks for the card while the screen should flicker, the same way it does in 3D.

Hope this will help some of you.

UT2003 Demo can be found here.
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[b]Optimization guidelines by Koji Ashida of NVIDIA:[/b][list][*]Use fx12 instructions whenever possible[*]Use lowest pixel shader version[/list][url=http://developer.nvidia.com/docs/IO/10878/ChinaJoy2004_OptimizationAndTools.pdf]source[/url]

[size=1]The politics are invading the technology. We don't really like to mess with politics because that kind of adversarial relationship has nothing to do with pure technical operations and the technical specifications of what we like to play with, the hardware![/size]
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