Getting 3840x2400 @ 13 Hz on DVI out of a T60p running Win7?

[bhtooefr]

I see no reason why it's not possible, but I'm having a lot of trouble getting it going, both with the Lenovo-approved 8.383 driver, and a Mobility Modded 8.593 installed via device manager.

I can get 1920x2400 @ 20 Hz no problem, and PowerStrip is saying it should do 3840x2400 @ 13 Hz, but...

For the T221 experts, it's a DGM (equivalent to DG5, but no converter box included.) EDID 29 is in use.

Any ideas?

Edit: Used EDID 03 (1920x2400 compressed to 960x2400 @ 50 Hz,) 06 (2624x2400 compressed to 1312x2400 @ 24 Hz, IIRC,) 21 (1920x2400 @ 20 Hz,) 22 (1920x2400 @ 24 Hz,) 36 (1920x2400 @ 24 Hz,) and 37 (1920x2400 @ 25 Hz.)

I'm using EDID 37 for now.

[bhtooefr]

I've also tried the 8.471 driver after mobility modding, which claims to support 3840x2400 @ 13 Hz on Vista. No change.

[bhtooefr]

Status update: Decided to try XP on a spare HDD, and found the following:

Driver and OS version really doesn't matter for this. Tried 8.533 for XP, same results.

So, I grabbed PowerStrip, and just started experimenting, because this XP install rebooted quickly.

3840x2400 was a no-go, of course.

So, I started playing with lower resolutions. I knew 2624x2400 worked, although I was using a dual-link mode on a single-link setup, so I tried a straight 2624x2400 mode. That worked perfectly.

Then, I tried for 4:3 - 3200x2400. No go.

So, I looked at the hex value, expecting something lying across some obvious boundary. 2624 = 0xA40, so I went for 0xB00, or 2816 - one over 0xAFF, if that was the problem. That worked, so I started experimenting.

I had previously read somewhere that Radeon X1xxx cards could only do 2900 horizontal pixels... well, my card is a Mobility FireGL V5200, aka the M56GL - basically an M56 (or Mobility Radeon X1600) with a different BIOS and different printing on the chip. So, I started playing.

I know ATI cards need their resolutions to be divisible by 8, so I went 2896, 2888, and then 2880.

2880x2400 is the maximum resolution that the chip can support, it seems. It can drive the monitor at 3840x2400, but only when scaling up from a VESA mode.

Interestingly, I see occasional artifacting at that resolution when there's video playing on the laptop's 2048x1536 panel... but on the laptop's panel, which hasn't been touched on timings or anything. My weakly educated guess is that there's some bus in the ATI chip that can only run so quickly, and when there's too much framebuffer data (like right now,) it gets overwhelmed. It's not timing issues with a TMDS transmitter - no artifacting on the external display, and the internal display is on LVDS anyway, not TMDS.

But, I've only got 960x2400 = 2.304 megapixels missing, out of 9.216 - one stripe of the striped mode that this monitor can run in, basically. That's not horrible. And, I've gotten 22 Hz out of the thing with tightened timings and running at 165 MHz DVI clock. Not bad at all.

[pianowizard]

How do you enjoy viewing this LCD? My main desktop is hooked up to three Dell 2407WFP's giving me 1920x1200x3 = 6,912,000 pixels, but that's still 25% fewer than what your T221 provides! But everything looks nice and big on my monitors so I can lean back on my chair and relax, whereas you probably need to maintain a distance of less than 10 inches! After adapting to such a high pixel density, your 15" QXGA screen will be so comfortable to use!

[bhtooefr]

I'm a weird case, in that my vision in my left eye is 20/20 uncorrected, but my right eye is amblyopic and hyperopic. So, I have bifocals to try to at least keep it from diving inward whenever I focus on something.

However, I'm not using the bifocal part of my lenses when using the T221, it's too far away.

When I'm using the T221, it's about arm's length away from me, and the ThinkPad is close to me (probably 18" or so.) At that distance, either monitor just overfills the center of my field of vision when I'm looking at it. (I can see well around the monitors, but to focus, I need to look around a little.)

I'm right on the edge of being able to comfortably use the T221 at those distances.

The QXGA is quite comfortable, though, compared to that - I could go for 250-300 PPI on the built-in screen.

[bhtooefr]

And, for the record, the fix is buying an Advanced Dock and a desktop FireGL V5200. (Edit: Actually, a V3400. Grr. Seller contacted, but it does work.)

Worked perfectly with the Lenovo beta drivers. 33 Hz (using PowerStrip) on two outputs.

Each output at 1920x2400, 80 kHz hsync, 48 pixel horiz front porch, 32 pixel horiz sync, 80 pixel horiz back porch, 33 Hz vsync, 3 line vert front porch, 10 line vert sync, 24 line vert back porch.

Due to Win7's lack of monitor spanning support (unless you get an Eyefinity card,) it's addressed as two separate monitors, but hey, it works.

http://bhtooefr.ath.cx/images/IMG_1326_small.jpg

[jketzetera]

And, for the record, the fix is buying an Advanced Dock and a desktop FireGL V5200. (Edit: Actually, a V3400. Grr. Seller contacted, but it does work.)

Worked perfectly with the Lenovo beta drivers. 33 Hz (using PowerStrip) on two outputs.

Each output at 1920x2400, 80 kHz hsync, 48 pixel horiz front porch, 32 pixel horiz sync, 80 pixel horiz back porch, 33 Hz vsync, 3 line vert front porch, 10 line vert sync, 24 line vert back porch.

Due to Win7's lack of monitor spanning support (unless you get an Eyefinity card,) it's addressed as two separate monitors, but hey, it works.

http://bhtooefr.ath.cx/images/IMG_1326_small.jpg

That is a very tempting setup.

I currently have a T61p QXGA Frankenpad with an advanced dock, hooked up to two 20" IPS 1600x1200 external monitors, enabling me to run my QXGA screen in parallell with the two external screens.

I have been hesitant to buy newer external monitors as I simply find the resolution too low for so large screens. I found out that at some time there existed kits for mounting 15" QXGA panels as external screens but I could not find any such kit for sale currently.

As I am unable to put together two external 15" QXGA screens my interest has turned to the T221. I would be very grateful if you could elaborate a bit on how it is using a T221 in different scenarios (web browsing, office productivity, watching videos etc...)

[bhtooefr]

Personally, I use the T221 mainly for reading PDFs and for static content that needs the resolution. It's not bad for office productivity if you don't mind leaning in, or zooming into your documents.

Web browsing is a bit much on it, and videos aren't a good idea - there's not enough bandwidth on the PCIe bus, really (there's only one PCIe lane in the dock,) and it bogs down even when moving windows around. (Speaking of, it'd be best if you used a similar chip to what you're using now. The desktop Quadro FX 570 or something in the GeForce 8600 family would be best. Not sure if that works properly with hotswapping, though.)