While installing Windows 7 64-bit, I ran into the 59Hz issue, where the refresh rate for the monitor can only be set to 59Hz; whenever I set it to 60Hz (which was available) it would revert to 59Hz. After some googling, I found two interesting threads:
http://forums.guru3d.com/showthread.php?t=301860
http://forums.techpowerup.com/showthread.php?t=100814&page=2
The guru3d post explains it's not really a bug; it's about a long-standing issue of 59.94Hz vs 60Hz and whether Windows rounds up or down; in Win7, 59Hz is actually 59.94Hz (read the whole original post, too long to quote here). However, some improperly coded games are affected by the issue. Those games include, and I quote the guru3d post, BF2 (and any sequel, or game based off the BF2 engine), WiC (works at 59hz according to pSXAuthor) and CoH.
In the techpowerup thread, post #20 further explains the issue, and suggests the problem extends to all DX10 games (but I have no way of knowing if it actually does).
Other comments in the threads showed that whether or not the 59Hz issue causes problems is highly variable: some displays have problems with this issue and some don't; some displays can have a problem with an HDMI connection but have no problem with a DVI or VGA connection; some dual display setups can have problems with this issue and some don't.
Post #33 of the techreport thread described a fix for nVidia cards, which I have modified slightly to reflect what I had to do:
- Go to Nvidia Control Panel
- Go to Add resolution
- Create Custom Resolution
- Click on Timing
- Click on Manual
- Set refresh rate to 60.001 Hz
- Press Test
- Restart Windows
This worked for my nVidia card running the 191.07 Win7 64bit driver, but I did need to restart Windows for the change to take effect; after applying this fix but before I restarted, my NEC 20WMGX2's OSD reported 59.7Hz; after the restart, it reported 60Hz. My other NEC 20WMGX2 on my Mac Mini reports 59.7Hz, even though it is set to 60Hz in the Displays System Preference.
Post #2 of the techpowerup thread quotes another techpowerup thread with a fix for ATi cards:
I don't have an ATi card so I can't comment further on the ATi fix.
http://forums.guru3d.com/showthread.php?t=301860
http://forums.techpowerup.com/showthread.php?t=100814&page=2
The guru3d post explains it's not really a bug; it's about a long-standing issue of 59.94Hz vs 60Hz and whether Windows rounds up or down; in Win7, 59Hz is actually 59.94Hz (read the whole original post, too long to quote here). However, some improperly coded games are affected by the issue. Those games include, and I quote the guru3d post, BF2 (and any sequel, or game based off the BF2 engine), WiC (works at 59hz according to pSXAuthor) and CoH.
In the techpowerup thread, post #20 further explains the issue, and suggests the problem extends to all DX10 games (but I have no way of knowing if it actually does).
When i couldnt use 60Hz, all my DX10 games would revert to 30Hz interlaced. Many games read the listing (in this order of priority)
60Hz (Progressive)
60Hz (Interlaced, aka 30Hz)
59Hz (progressive)
50Hz (Progressive)
When 59Hz is chosen in windows or is supported in the game - no problem. But when it doesnt work, the games chose the "next best" thing - which isnt 59Hz, they think 60Hz interlaced is higher than 59 progressive, so we get 30Hz.
Other comments in the threads showed that whether or not the 59Hz issue causes problems is highly variable: some displays have problems with this issue and some don't; some displays can have a problem with an HDMI connection but have no problem with a DVI or VGA connection; some dual display setups can have problems with this issue and some don't.
Post #33 of the techreport thread described a fix for nVidia cards, which I have modified slightly to reflect what I had to do:
- Go to Nvidia Control Panel
- Go to Add resolution
- Create Custom Resolution
- Click on Timing
- Click on Manual
- Set refresh rate to 60.001 Hz
- Press Test
- Restart Windows
This worked for my nVidia card running the 191.07 Win7 64bit driver, but I did need to restart Windows for the change to take effect; after applying this fix but before I restarted, my NEC 20WMGX2's OSD reported 59.7Hz; after the restart, it reported 60Hz. My other NEC 20WMGX2 on my Mac Mini reports 59.7Hz, even though it is set to 60Hz in the Displays System Preference.
Post #2 of the techpowerup thread quotes another techpowerup thread with a fix for ATi cards:
-Open CCC
-Navigate to the Attributes Tab
-Check off Reduce DVI Frequency on High Resolutions Displays
-Change the Refresh rate to 60Hz
-Right Click on the Desktop > Screen Resolution > Advance Settings > Monitor Tab > Change Screen Refresh Rate to 60Hz
-Done (you can reboot to see if the refresh rate sticks)
Addendum
Only use the above fix if this allows your monitor's on screen display (OSD) to read 60Hz refresh rate (Typically we are talking about a resolutions of 1920x1200. Other refresh rates may vary on resolution). If your monitor's OSD read's 59Hz as a refresh rate revert the setting in CCC and win7 back to it's original state. Check again to make sure that your OSD reads 60Hz this time. You may need to reboot before your screen reads 60Hz again (pending that you know for a fact that your monitor always read 60Hz as a refresh rate at that resolution). For Radeon users this means all you do is install your Cat Driver. Don't make any changes to refresh rates in CCC. For others there maybe another way to fix it.
“If you have a monitor that exposes ~59.94 (and no other frequency that we would use for 60), we enumerate both 59 and 60 and whichever you set, we set 59.94 and persist 59.94. When the UI asks what mode we’re in we tell it we’re in 59, as you see. This is the issue we had back at the end of February when we were trying to make the last minute fixes but in the end we decided that it was too late. So it is by design for now.”
I don't have an ATi card so I can't comment further on the ATi fix.
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