Reducing a computers EMI improves picture quality of attached monitors.

JasonM

JasonM

JasonM

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I've just made an accidental discovery or least to myself, I was reducing EMI into my computer in an attempt to improve output from an Asus Essence STX II card.

By reducing EMI going into a computer, the picture quality of all attached monitors improves. I can only assume EMI goes into a computer by the mains, then travels via the graphics card into the digital connections, then enters the monitors. The improvement in picture quality is not small, but significant.

PSU is a Seasonic Prime Platinum 760. Graphics card is Quadro P620. Triple Ag Neovo Monitors connected by double shielded DVI connections, improvement is seen on all 3 screens. Case is an all metal Silverstone FT-02

The reduction in EMI was done using a Tacima CS947 and a 2 meter Russ Andrews classic powerkord.

After I found this I immediately googled 'EMI effects on DVI' and found a research paper on this exact subject.

EMI ANALYSIS OF DVI LINK CONNECTORS
MISSOURI UNIVERSITY OF SCIENCE AND TECHNOLOGY

https://scholarsmine.mst.edu/cgi/viewcontent.cgi?article=8407&context=masters_theses

Others could try the same if wishing to improve picture. I've been on the OCUK forum since 2009, and don't recall anyone else posting about this subject before.
 
shankly1985 said:
Not read the link but does this also improve displayport and hdmi?
Also is this something you can showcase the difference?
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It should work on HDMI and yes to displayport also. My Quadro P620 uses a displayport to DVI adapter.

Can't demonstrate, don't have a camera sensitive enough to show the difference.

Anyone interested in this should trust and verify for themselves.
 
So you bought a £40 6 way mains extension lead/adapter, and a £??? posh kettle lead? You believe the picture quality improved in what way?
 
jaybee said:
So you bought a £40 6 way mains extension lead/adapter, and a £??? posh kettle lead? You believe the picture quality improved in what way?
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I've been using the Tacima mains conditioners for years, I have 6 at various places in the house. One thing the Tacima's do is remove DC that gets injected into the AC from LED transformers.

I already own other Russ Andrews cables I buy them second hand from eBay, that classic cable was £50. They use twisted pairs that counter EMI build up in the cable.

Picture is sharper / text is easily to read, less pixel bleed.

I'm a software engineer, this is my home office, anything to improve screen quality is a bonus. I already have professional glass fronted screens, Ergotron triple lift stand, BenQ Screen Bar, BenQ desk lights.

EDIT. I'm looking at these screens now, and the black parts of the screen are blacker. There is more contrast in the colours, but it's not the normal way by increasing contrast (where everything gets blown out), the contrast is there because there is less bleed and the darker areas (that should be darker) are darker. I've made no changes to any monitor settings, the changes are only from the other things mentioned
 
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Interesting Jason.

can you confirm the 3 monitors you are using and mentioned? Are all three being tested via the DP to DVI adapter and therefore DVI input in to the monitor?
 
Baddass said:
Interesting Jason.

can you confirm the 3 monitors you are using and mentioned? Are all three being tested via the DP to DVI adapter and therefore DVI input in to the monitor?
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There 3 x Ag Neovo E-W22 glass fronted that I've used for many years. All the monitors are connected by DVI, the Nvidia has a mini DVI to DVI adapter for each cable.
 
Can't see any difference between my PC and a decent monitor mains powered and the same monitor but powered via battery and from a laptop also on battery without any mains connection - PQ looks identical.
 
JasonM said:
There 3 x Ag Neovo E-W22 glass fronted that I've used for many years. All the monitors are connected by DVI, the Nvidia has a mini DVI to DVI adapter for each cable.
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I'd be interested to hear about further testing from more modern monitors if you ever have chance, as I think it's probably more likely the difference is down to those older models, which to be honest i've never even heard of, and/or the DP > DVI convertor. A modern screen from a main manufacturer, using HDMI or DisplayPort connection with no convertor I suspect would not show any of the differences that you've described.
 
Eh, they are digital interfaces, are you claiming to send better quality ones and zeros :D

DVI can carry analog signal but most installs are digital, as is HDMI and DP.
 
SupraWez said:
Eh, they are digital interfaces, are you claiming to send better quality ones and zeros :D

DVI can carry analog signal but most installs are digital, as is HDMI and DP.
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i'm just saying the nature of the convertor adapter is an unknown quantity here that wouldn't be necessary on any modern screen.
 
Baddass said:
i'm just saying the nature of the convertor adapter is an unknown quantity here that wouldn't be necessary on any modern screen.
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For resolution of those monitors it's passive mechanical adapter.
No matter if it's DP or HDMI port in card, both are backwards compatible/support outputting single link DVI.
 
Interesting, the tacima you recommended improved audio quality. Will have to check this with the psu plugged into it as well to see if there's any difference.
 
EsaT said:
It doesn't remove any DC, but the opposite: Higher frequency AC components.

And talking about picture quality while having some medieval old TNs...
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AC makes a lot more sense.

Had to look them up and they do indeed look ancient. Almost like someone wanted a bezel larger than on a CRT:
gkSkcp4.png
The images of the back seemed to show the stand as being fixed, but a review said that VESA mounting was possible.
 
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