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31109
U2713HM, max resolution with a laptop lacking DVI and DisplayPort?
This is kind of an answer to an earlier post of the same title. However, the forum interface does not seem to allow a reply on older posts even though they are unanswered and have subscribers. Ho-hum. Anyway, I have discovered that I can drive the U2713HM using a simple HDMI cable from a laptop by using the nVidia Control Panel display property interface ("Change Resolution" page) and setting a custom resolution to match the full 2560 x 1440. The trick is to use the Customize button and create a "custom resolution" for 2560x1440 32 bit progressive, use "Automatic" and then drop the Refresh Rate (Hz) down to around 38Hz - 41Hz. Find one that works and then keep trying new ones in 1-Hz increments until it fails. I'm driving the monitor (normally connected by Dual link DVI to a desktop machine) from a Toshiba Qosmio laptop using its (only available) HDMI output by using a refresh rate of 41Hz. Anything higher and the display will not "lock-in" to its native resolution. This then allows me to use the input selector on the display to switch between my desktop PC and the laptop. Works a treat! :emotion-2:
BigAlUK
6 Posts
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January 1st, 2014 02:00
Just thought I'd add that:
This might be possible as a work-around to other cable option problems - for instance, low quality or long length cables - where the essential problem is one of bandwidth supported by the cable or the interface type. By lowering the refresh rate, you are lowering the bandwidth requirement. For old CRT displays, this usually resulted in a significant dimming - not so noticeable with LCD/LED technologies! And remember that the eye can integrate cini-film at rates as low as 25 Hz! So setting the refresh rate to 30-48 Hz on a modern LCD/LED is now a viable workaround for cable bandwidth problems. Note however that not all problems may be addressed by this: for instance I had a single-link DVI cable for which no stable frequency could be found (the monitor really does need Dual-Link DVI - the one with a full set of pins).
BigAlUK
6 Posts
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January 1st, 2014 06:00
Oh - And happy New Year everyone!
:emotion-22:
BigAlUK
6 Posts
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January 3rd, 2014 15:00
Slight correction: Usually you have to set "CVT Reduced Blank" mode on the NVidia custom resolution - not automatic.
It turns out that NVidia "does its own thing" on automatic and for HDMI/VGA will probably get it wrong. If you choose "Reduced Blank", then it is more likely to work. Setting "Reduced Blank" and then setting "Manual" also works, because the reduced blank time settings are placed as a starting point for the manual operation! NVidia then "learns" what you did with these options and configures it as "Automatic" for the next time around (hence the earlier confusion when I said use Automatic - I hadn't used Automatic, but NVidia recorded it as Automatic, the sly b'tards). Anyways, I've tried this with two different HDMI setups and one VGA, and in all cases got the full 2560x1440 resolution. However, only with HDMI would it lock-on to pixel-perfect rendition. In VGA mode, the signal is already "corrupted" by being analogue, so all you will get is an analogue approximation that looks like what you used to get from CRT monitors. In fact, VGA looks better at lower resolutions anyway. In short: this is a solution for HDMI really, not VGA.
Incidentally, I had some problems with the HDMI-driven monitor randomly "disconnecting" (which is something widely complained about on the net in general about HDMI displays). This appears to have stopped once I uninstalled the Dell "Display Manager" software. It seems that some sort of conflict arises between this software and the NVidia software which occasionally results in the HDMI Monitor disconnection. Whilst not greatly researched, I am basing this assumption on the fact that removing the Dell software stopped the disconnections occurring. Don't really care where the "blame" lies (Dell or NVidia) - just glad that it has stopped!
BigAlUK
6 Posts
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January 3rd, 2014 15:00
In fact, since "Entech" are behind just about any low-level display driver code, I'll blame them! :emotion-2: ...bit then I'll recall that Entech gave me such joy decades ago when they first made CRT-display tweaking software available to the great unwashed, and forgive them already!