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I'm simply confused at this point. It has to be a software issue...

Had to take the borrowed 750 Ti out of my rig for today, so I'm back to the 4790K with HD 4600 graphics. Except the highest resolution offered is 1600x1200 when it should be 2560x1600. Same display and DVI-D cable that worked previously @ 2560x1600 in the past using the same HD 4600. Literally nothing has changed from the last time it worked correctly. 

Tried uninstalling the Intel drivers (wasn't even listed under Add/Remove Programs and had to do it via the device manager). Reseated the cable, checked the connector for damaged pins, and tried three different installs of Intel's driver.

Intel did add the ability to create a custom resolution to their drivers. But when I manually configure it to 2560x1600 60z it pops up a window saying "not enough bandwidth" and refuses to create the profile. Even tried 59hz since that's an old issue with Dell firmware with no change.

I'll get the 750 Ti back later today, but I really hate nonsensical issues like this. Any ideas?

Sounds like the DVI port is running in single-link mode (AFAICT this is a limitation of the HD 4600), and is having its dot clock capped. I'm seeing some Google results that imply the Windows driver is capping the dot clock, as people are apparently able to run at 2560x1600 under Linux but not Windows.

I believe resolutions above 1920x1200 are technically out-of-spec for single-link DVI, but in theory could work since DVI uses the same electrical signaling as HDMI (which supports 2560x1600). Maybe older Windows drivers were not strictly enforcing DVI spec?

If the onboard has an HDMI port, try using that instead. If you have an HDMI port but don't have an HDMI cable handy (or if the monitor doesn't have an HDMI input), a passive HDMI-to-DVI adapter might even be enough to fool the driver into allowing the higher resolution.

just brew it! wrote:

Sounds like the DVI port is running in single-link mode (AFAICT this is a limitation of the HD 4600), and is having its dot clock capped. I'm seeing some Google results that imply the Windows driver is capping the dot clock, as people are apparently able to run at 2560x1600 under Linux but not Windows.

I believe resolutions above 1920x1200 are technically out-of-spec for single-link DVI, but in theory could work since DVI uses the same electrical signaling as HDMI (which supports 2560x1600). Maybe older Windows drivers were not strictly enforcing DVI spec?

If the onboard has an HDMI port, try using that instead. If you have an HDMI port but don't have an HDMI cable handy (or if the monitor doesn't have an HDMI input), a passive HDMI-to-DVI adapter might even be enough to fool the driver into allowing the higher resolution.

Does the same apply for DisplayPort? I'm running my monitor from my Motherboard's DisplayPort connector, through a DP->DVI adapter (not sure if its single or dual). I only have a 1080p monitor at the moment but may get a larger one in the future.

I'm also using the HD4600 on my 4790K because I don't play games and so don't need a graphics card. That said, I run Linux, not Windows.

Just Curious.

srg86 wrote:

Does the same apply for DisplayPort? I'm running my monitor from my Motherboard's DisplayPort connector, through a DP->DVI adapter (not sure if its single or dual). I only have a 1080p monitor at the moment but may get a larger one in the future.

I'm also using the HD4600 on my 4790K because I don't play games and so don't need a graphics card. That said, I run Linux, not Windows.

Just Curious.

This table lists the resolution limitations by DisplayPort version.

So your resolution is potentially going to be capped by: the version of DP supported by your motherboard, the version of DP supported by the DP->DVI adapter, whether the DP->DVI adapter and monitor both support dual-link or not, and any software/driver limitations (like the one the OP seems to have hit).

So "it depends".

just brew it! wrote:

srg86 wrote:

Does the same apply for DisplayPort? I'm running my monitor from my Motherboard's DisplayPort connector, through a DP->DVI adapter (not sure if its single or dual). I only have a 1080p monitor at the moment but may get a larger one in the future.

I'm also using the HD4600 on my 4790K because I don't play games and so don't need a graphics card. That said, I run Linux, not Windows.

Just Curious.

This table lists the resolution limitations by DisplayPort version.

So your resolution is potentially going to be capped by: the version of DP supported by your motherboard, the version of DP supported by the DP->DVI adapter, whether the DP->DVI adapter and monitor both support dual-link or not, and any software/driver limitations (like the one the OP seems to have hit).

So "it depends".

Ahh well here's from Asus's website on the Z-97A:

Integrated Graphics Processor- Intel® HD Graphics support
Multi-VGA output support : HDMI/DVI-D/RGB/DisplayPort ports
- Supports HDMI with max. resolution 4096 x 2160 @ 24 Hz / 2560 x 1600 @ 60 Hz
- Supports DVI-D with max. resolution 1920 x 1200 @ 60 Hz
- Supports RGB with max. resolution 1920 x 1200 @ 60 Hz
- Supports DisplayPort with max. resolution 4060 x 2160 @ 24 Hz / 3840 x 2160 @ 60 Hz
Maximum shared memory of 512 MB
Supports Intel® InTru™ 3D, Quick Sync Video, Clear Video HD Technology, Insider™
Supports up to 3 displays simultaneously
DP 1.2 Multi-Stream Transport compliant, supports DP 1.2 monitor daisy chain up to 3 displays

That may even help  the OP. Now now the Corei7 4790K CPU on Ark (maybe I should have just Googled before asking, but maybe this maybe of help to others):

Max Resolution (HDMI 1.4)‡	3840x2160@24Hz
Max Resolution (DP)‡	3840x2160@60Hz
Max Resolution (eDP - Integrated Flat Panel)‡	3840x2160@60Hz
Max Resolution (VGA)‡	1920x1200@60Hz

Curious that DVI isn't mentioned, maybe more down the mainboard. Not sure about my adapter either.

Damn, thanks for the find JBI! 

Bugged the heck out of me because I was 99% sure I had used this monitor & DVI out in the past, but apparently I simply remember it wrong. Indeed the motherboard DVI is limited to 1920x1200.

It is still odd I don't at least have the option to use 1920x1200, I have done so regularly with the Dell 2407 on these boards. 1600x1200 just seems badly distorted by comparison. 

Thanks SRG86, that was the first place I went after I saw JBI's post. It's a Z97 board so the graphics output table matches exactly.