Yamakasi Catleap 27" 100mhz IPS

MOOGLEYS · 13 May 2012 at 00:22

Phunky said:
My second Yamakasi (100hz model ) has just left Germany, fingers crossed it will be with me by Monday. Been expensive in the long run to get this model but hopefully be worth it to have 2560x1440@100hz.

Do these still use the same panel and overclock ? If so it is meant to put huge strain on the panel which is only rated at 60hz. I did read something about LG testing the panels at higher than 60hz rates and the failure rate was almost %100 after a short period. I will try and find the article.

Phunky · 13 May 2012 at 00:33

It's the same panel, but has different PCB which allows for double the bandwidth (or something along those lines)

I've not heard anything about them dying and quite a number of people have been running the 2B model at 100+ for some time.

MOOGLEYS · 13 May 2012 at 00:36

I will try and find the article I was reading. LG said the panel cannot handle the increased refresh rate and the manufacturers using hardware to overdrive them are severely limiting the life of the panel..

Might have just been LG not wanting people trying to get more for nothing so to speak.

Phunky · 13 May 2012 at 00:40

Would be interesting if you can find it

there are 100 of us who will be getting this latest "extreme" version of the Yamakasi so I guess we will find out soon enough if it will kill the panels

MOOGLEYS · 13 May 2012 at 00:46

Going by the circuit in that pic it seems the board just sends two signals to the panel. I'm not overly sure but that to me would be interpolation which is not true 120hz and would cause quite a bit of input delay and no real improvements over a 60hz image.. ? Maybe that is how they manage to kind of say it's 60hz or over. Bit like something having two 64bit buses but being advertised as 128bit.. ??

I could be wrong which is always very likely...

melmac · 13 May 2012 at 00:49

Well, the 2B models have only been available since feb. So the longest anyone can have one of these monitors is between 3 and 4 months. 4 months isn't really a long time, we really have no idea yet how the overclocking affects these monitors or how long they will last at such high refresh rates.

It's just too early to tell.

And another thing we have to remember is that these are A- panels, so they have already failed some sort of quality control check. Since there seems to be very few dead pixels been reported my guess is that there is another defect in the panels.

MOOGLEYS · 13 May 2012 at 10:59

Found this which is quite interesting.

2560x1440 @120hz needs 15.75Gbit of Bandwidth. The max that can be fed down a dual link DVi is 9.9Gbit.

Even running 2560x1440 @ 85hz is still needing 11.16Gbit of bandwidth.

2560x1440 @ 60hz requires 7.87Gbit which is within tolerances so around the max that can be fed down a dual link Dvi is 2560x1440 @ 75hz using 9.84Gbit...

According to this it is not possible to feed anything above 75hz with 2560x1440 if using a dual link DVI.

1920x1080 (1080p) @ 120hz uses 8.86Gbit and is within tolerances. It seems the only way you will get 120hz is to use a display port V1.2 connection and from what I have been reading this is why there are no 2560x1440 120hz screens as of yet.

:confused:

Screen bandwidth calculator

no_1_dave · 13 May 2012 at 11:00

I haven't checked if mine is B or C but if I did overclock it I would only run it higher then 60Hz while gaming, then I'd drop it back again to prolong the life.

no_1_dave · 13 May 2012 at 11:04

MOOGLEYS said:
Found this which is quite interesting.

2560x1440 @120hz needs 15.75Gbit of Bandwidth. The max that can be fed down a dual link DVi is 9.9Gbit.

Even running 2560x1440 @ 85hz is still needing 11.16Gbit of bandwidth.

2560x1440 @ 60hz requires 7.87Gbit which is within tolerances so around the max that can be fed down a dual link Dvi is 2560x1440 @ 75hz using 9.84Gbit...

According to this it is not possible to feed anything above 75hz with 2560x1440 if using a dual link DVI.

So any 120hz screen using a dual link DVi must be using interpolation to achieve 120hz which is kind of cheating....

Screen bandwidth calculator

That's interesting, looking at that calc shows how limited even displayport 1.2 is. When 4k screens start becoming main stream DP1.2 can't even handle it at 120Hz.

Phunky · 13 May 2012 at 11:08

Wikipedia doesn't seem to state a limit for DVI-D

(Single) WUXGA (1,920 × 1,200) @ 60 Hz
(Dual) Limited by copper bandwidth limitations, DVI source limitations, and DVI sync limitations.

chipachap · 13 May 2012 at 11:16

MOOGLEYS said:
Found this which is quite interesting.

2560x1440 @120hz needs 15.75Gbit of Bandwidth. The max that can be fed down a dual link DVi is 9.9Gbit.

Even running 2560x1440 @ 85hz is still needing 11.16Gbit of bandwidth.

2560x1440 @ 60hz requires 7.87Gbit which is within tolerances so around the max that can be fed down a dual link Dvi is 2560x1440 @ 75hz using 9.84Gbit...

According to this it is not possible to feed anything above 75hz with 2560x1440 if using a dual link DVI.

1920x1080 (1080p) @ 120hz uses 8.86Gbit and is within tolerances. It seems the only way you will get 120hz is to use a display port V1.2 connection and from what I have been reading this is why there are no 2560x1440 120hz screens as of yet.

Screen bandwidth calculator

+1....I think. I was curious as to how people are getting to 100hz with DL-DVI. Seems it is interpolation and not 'true' 120hz. DisplayPort 1.3 or 1.4 will probably support it.

MOOGLEYS · 13 May 2012 at 11:22

You are also limited buy the GPU's 400mhz clock which will not allow anywhere near 120hz at 2560x1440. AMD limit this to 330mhz and Nvidia cards can ignore this by setting a custom res but anything over 85hz is ignored...

More :confused:

Limits of connections

Dual-link DVI - 330 MHz
DisplayPort 1.0/1.1 - 288 MHz
DisplayPort 1.2+ - 576 MHz

Phunky · 13 May 2012 at 11:26

MOOGLEYS said:
You are also limited buy the GPU's 400mhz clock which will not allow anywhere near 120hz at 2560x1440. AMD limit this to 330mhz and Nvidia cards can ignore this by setting a custom res but anything over 85hz is ignored...

More

Limits of connections

Dual-link DVI - 330 MHz
DisplayPort 1.0/1.1 - 288 MHz
DisplayPort 1.2+ - 576 MHz

This is true, so far the only cards that have hit 120hz was a single 680 as that seems to be able to go above 400mhz pixel clock but SLI does not work.

It's also expected that the 670 will be able to handle this.

MOOGLEYS · 13 May 2012 at 11:32

But even if the cards can hit 120hz you will be limited by the bandwidth of dual link Dvi which will cause the GPU to either drop to a usable value or cause quite a large delay in sending signals.

To me it seems the benefit of anything over 75hz is likely to be wasted on transmission losses or the GPU will simply drop to a manageable level what ever it is set to output..

Phunky · 13 May 2012 at 11:48

MOOGLEYS said:
But even if the cards can hit 120hz you will be limited by the bandwidth of dual link Dvi which will cause the GPU to either drop to a usable value or cause quite a large delay in sending signals.

I can't find any spec that states a limit on DVI-D though

http://en.wikipedia.org/wiki/Digital_Visual_Interface#Specifications said:
Dual link maximum data rate is limited only by the bandwidth limits of the copper the DVI cable is constructed of and by the DVI signal's source.

The only way we have to confirm the overclock is via Powerstrip and by enabling vsync in games, which both display the expected values. If the GPU was dropping to a usable value this would effect vsync and if there was a delay it would be unusable in games or least i'd suspect it would.

MOOGLEYS · 13 May 2012 at 11:58

Its on Wikpedia. Basically dual link doubles the single link requirements.

he DVI specification mandates a maximum pixel clock frequency of 165 MHz when running in single-link mode. With a single DVI link, the highest supported standard resolution is 2.75 megapixels (including blanking interval) at 60 Hz refresh. For practical purposes, this allows a maximum screen resolution at 60 Hz of 1,915 × 1,436 pixels (standard 4:3 ratio), 1,854 × 1,483 pixels (5:4 ratio), or 2,098 × 1,311 (widescreen 16:10 ratio).

To support display devices requiring higher video bandwidth, there is provision for a dual DVI link. A dual link doubles the number of TMDS pairs, effectively doubling video bandwidth at a given pixel clock frequency. The DVI specification mandates how the dual link may be used. All display modes that use a pixel clock below 165 MHz, and have at most 24 bits per pixel, are required to use single-link mode. All modes that require more than 24 bits per pixel, and/or 165 MHz pixel clock frequency must use dual-link mode. In modes where each pixel uses 24 bits of color data per pixel or less and dual-link mode is in use, the transmitter stripes pixel data across both links; each sequential video pixel is transmitted on alternate links. In modes with color depth greater than 24 bits per pixel, the second link carries the least significant bits of each pixel.

The DVI-D dual link version has 25 pins - the pin configuration is similar to DVI-D single link with 24 pins arranged in 3 rows of 9 pins each, with a flat pin at the side. This configuration supports video pixel rates up to 330 MHz. With twice the bandwidth of a single link connection, this configuration can support all HDTV resolutions, as well high-end computer graphics and/or higher refresh rates.

MOOGLEYS · 13 May 2012 at 12:10

There is a detailed PDF guide here...

DVI Spec

Phunky · 13 May 2012 at 12:14

Yeah, but the same page of Wikipedia also states that Dual-Link is only limited by the copper and the dvi source. Either way people have been running these at 100hz+ so i'll just wait till I get mine and see if I notice any difference between this and my current 120hz monitor.

MOOGLEYS · 13 May 2012 at 12:23

Phunky said:
Yeah, but the same page of Wikipedia also states that Dual-Link is only limited by the copper and the dvi source. Either way people have been running these at 100hz+ so i'll just wait till I get mine and see if I notice any difference between this and my current 120hz monitor.

The software will try and run it 100Hz but the hardware will not allow it so will drop it back until it can be transmitted.

From what I have read and understand once the card hits it's bandwidth limit depending on the card it will just either hit a huge signal delay or the card will limit the frequency automatically. So even if you are telling it to try and output 100hz @ 2560x1440 it is more than likely not.

You unfortunately cannot beat the limits of the transmission system.

rob77 · 13 May 2012 at 13:02

Hi guys

After reading through all the posts on here I'm still none the wiser. Which seems to be the best make to go for or are they all the same? Who is the best seller? Also is it best to go for one with glass front?

Cheers