Overclocking Monitors

Judas

Strange, not many people even think about "ocing" a monitor.... but it's quite possible... in more then one way to... but it's easiest with just the refresh rate..... safest to if you monitor is rather new and has the ability to show "refresh rate out of range" or similare message..

some monitor have a locked in refreshrate at whatever resolution...

some of which state in the specs for example "1024x768 @ 100hz"

any attempt to go beyond 100hz results in a out of range problem..... This is an occurance of being hardlocked and programed to automatically kill itself... instead of "trying" out the new refresh rates


I had a older 19" KDS 190 orginal sitting here...

Heres a spec list:

DOT PITCH: 0.27
Maximum resolution: 1600x1200
Maximum Refreshrate at max res: 60hz

Resolution~Max Hz
640x480~160
800x600~120
1024x768~100
1152x864~85
1280x960~85
1600x1200~60

With a program that would allow you to SPECIFY a specific refresh rate and a video card that supported this, i was able to obtain the following:

640x480~164hz (blah)
800x600~ 137hz (intersting but... doesn't matter)
1024x768~110hz (just about 120 which i find OPTIMAL for gaming with v-syc)
1152x864~ 101hz (hey, not bad at all)
1280x960~ 95hz (i'll take it)
1600x1200~ 83hz (what-d-ya know, i now could run 1600x1200 for my desktop resolution all the time)

i basically did what i would do with anything else i'd overclock.. start with a 10hz increase ... if it worked.... i'd bump it another 10.... if it didn't... i'd drop it down 5... if it didn't i'd drop it back down 1 at a time..... oventually finding a spot were the "sync out of range" error no longer appeared OR i didn't see any weird things happening...

WARNING though, highly dangerous, you could completely destroy a perfectly good working monitor by doing this... and or damage something else..... A monitor is a fine tuned peice of hardware... like anything else electronic...they can go up in smoke rather easily...

Anyone else every oc a monitor?

Shinjikun

Which program did you use to accomplish this in your case?

Razgriz

yea, id like to know, cause my 76v Samtron at 1280x1024 is only 60hz

Judas

ReFreshForce will do it....

i know there are a few dozen tools out there that will alow you to put in specific refreshrate value... force it... test it.... and automatically allow you to come back to windows if 15 seconds pass OR hitting escape.....

Just be hella careful... no one is responcible for anything that may happen to your montior/your computer.. OR YOU..... other then yourself...

sometimes you get luck... sometimes you don't.... running higher refreshrates could and mostl ikely decrease your monitors lifespan as well..

Matth

The horizontal rate is where you wil get pain - You should not have problems, moving the vertical refresh rate, so long as the horizontal rate (roughly, V-rate x V-res) does not exceed the maximum used in any of the monitors supported modes) - it's also unwise to exceed the highest normally used V-rate.

The limiting factor is the line output stage, just like a CPU, if you run it faster than intended, it may overheat or break down in other ways, and it's a highly stressed component, dealing with high voltages and surges under normal conditions.

For the KDS above, the highest supported rate is at 960 x 85 = 81600
so at 1600x1200, anything over 68Hz risks overstressing it.

83 is way too high, pull it back to 70, or 72/75 at the most, and it'll probably hold it.

Matth

http://www.samtron.com/product/76v_fea.html
65Hz, it says here

Horizontal scan, 30-70kHz - so it might manage 70Hz at small risk ... 68 Hz actually brings the horizontal rate to 70k

Logla

personally I think you would have to be incredibly stupid to want to do this.

If you damage the monitor enough to damage the tube, you could end up dead.

I certainly wouldn't want the big glass tube which is no more than 2 feet away from my face to suffer a nasty failure like that.

All it takes is for something on the board to blow to cause the tube to crack and if that happens you could be decapitated or at best, severley disfigured.

Zardon

i used to have a 19 inch screen that would according to the manufacturers specifications only hit 70hz at 1600x1200, with powerstrip it was possible to hit 78hz. I ran it at 75hz for many months as anything under 75hz on a CRT gives me a headache so for that it was useful.

I am no monitor technican and perhaps someone should point swimtech in the direction of this thread, im sure his viewpoints as a technican in this field would prove useful.

Logla

I'm sure a couple of hertz aint gonna do too much damage or cause too much danger.

But, I'm sure there are some monitors that are just not going to like it and personally when something is made of glass, holds a vacum and sits a couple of feet from my head I would approach this with caution.

I'm just a scaredy lil' wimp though.

swimtech

Indeed, the warnings here by Judas and Logla are well to be taken into consideration.

Of course it's possible to "overclock" a monitor. Consider this though - when you overclock a processor or GPU, most who do that take precautions that include beefing up the cooling for the processor and/or the memory, raising voltages (which helps to keep power consumption more even throughout the system), getting a power supply with more reserve power (headroom), etc. There just isn't a way to do that with a monitor that I'm aware of - they are not constructed in modular fashion as are computers (well, Zenith and Quasar TV's used to be, but...). No way to effectively upgrade the parts in a monitor to handle the overclock (except raising voltage ratings on capacitors by replacing them - and very specific capacitors at that...). If the monitor doesn't smoke itself, as Judas said, it's life will be shortened. Guess you can tell I really don't think it worth the effort.

In addition, a monitor designed to run at a max of 1280x1024 at 70hz cannot (!!!) display a crisp image at 1600x1200 at 70hz. The internal clocks (crystals or tank circuits - RC networks, etc) that drive the chips that drive the output transistors that drive the CRT electron guns just can't keep up. Displaying video or game screens masks the lack of crispness, but text shows up looking mushy... Finally, it's rare, but CRTs have been known to blow up. The neck is the weak part of the glass tube which generally shatters first, then is sucked by the high vacuum from the back of the tube toward the front glass and could theoretically burst through - showering glass and a fast moving projectile that weighs about a quarter pound (the gun assembly) toward the users face!

That being said, Judas, how does your KDS look running at 1600x1200 @83? I'm also noting you're using a monitor with a few years on it and willing to sacrifice it for your experiment...

swimtech

Oh, and sorry for the double post but this is important.

Anytime you push a monitor beyond the rates it is designed to work at, the percentage of uncontrolled high energy electrons emitted from the guns in the CRT hitting the metal shadow mask or vertical metal wires increases. Whenever a high energy particle hits a piece of metal, one of the byproducts is X-RAYS!

Those under 40 in these forums probably don't remember being told to sit back from their TV years ago (the X-Ray protection is much better now - but it is that way by design for that TV or monitor), but that was why. And that monitor screen is only 2 feet away - you will have more X-ray exposure if you push a monitor beyond its designed parameters and X-rays do increase the likelihood of cancer.

Shinjikun

Wow; good information swimtech.

Thanks!

Judas

I was hoping to get swimtechs attention on this as i was wondering more about the harm that could be done and more information on what could be see as a pro or CON...

1600x1200@83hz, with the dot pitch of 0.27, it looks just a slight bit tad blurrier then before... but at that resolution it always did... the monitor wasn't of any high quality standards.... cheapest 19" i could find and buy.... and low and behold.. it's still working flawlessly... (although at defaults )

i haven't attempt to really OC my current 900IFT.. i have really no reason to ATM... i haven't any wish to possibly kill a extremely expensive monitor with quite abit even today...

Matth

One thing, on Digital control monitors with "Out of Range" warning, they SHOULD refuse to display any signal that is unsupported.

On analog control monitors, the fact that it DOES lock in to a particular scan rate, is no certainty that it can hold it safely - by definition, if it takes the scan rate outside the supported range, then it is NOT designed to handle it.

When you overclock a CPU, it may crash, if you push it past stability - you'd be very unlucky to kill it, unless you ignore temperature or other symptoms.

If you push a monitor too high in scan rate, the first you'll know about it is when it breaks down.

CHRONICse7en

Why would you want anything faster than 85mhz 1280 by 1024 up anyway pic just would get a slight haze

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BWX

I have a 17" KDS Xflat that will run 1200 x 900 @ 75hz with Omega's - but when I use regular CAT drivers, that res isn't available.. I don't really think that res is "OC'ing" my monitor, but that res and refresh isn't available normally.. Like right now with the latest Cat beta's..

MythicaL

Trying 1280x1024 @ 85hz... when it should be 60hz... It still bothers my eyes though.

Dom

I'm running my monitor out of spec, 1280x1024 @ 85hz, but I don't know if I'd call it an OC. Though I guess technically that is what an OC is.

Vampyromaniac

that's out of spec? what's the normal refresh at 12x10?