In the market for a new g/card - 290/780/7990?

oweneades · 17 Jun 2014 at 15:41

snips86x said:
I've just found an EVGA 780 SC on the MM for £400, so really debating where to go.....I'll leave the testing to you!

Oh - Will be moving to a 1440p monitor also over the coming months.

At that sort of money I would be looking new.

Either this: 290 Tri-X

or, actually no, the 780 is not worth another £50 over the Tri X cooled 290.

If you can get a nice 780 around £350 then that would also be an option.

LtMatt said:
Well if you run the fans at 65-75% you will have no trouble keeping temps in check. I will do a couple of tests using my undervolted settings and see what i get. If you undervolt the core and AUX (easily possible if you run stock) and save it to a profile in afterburner you can apply that profile when the pc boots up. This will help keep temps down nicely and can enable you to run a slower fan speed. I use -0.031v and -0.100mv AUX for stock clocks of 975/1250. I will report back tomorrow morning with the results.

Agreed with Matt. 65-75% is noisy but temps stay in the low to mid 80's for me in a Corsair 250D. Custom cooled 290's solve the noise problem and keep the temps in check.

snips86x · 17 Jun 2014 at 15:42

LtMatt said:
Well if you run the fans at 65-75% you will have no trouble keeping temps in check. I will do a couple of tests using my undervolted settings and see what i get. If you undervolt the core and AUX (easily possible if you run stock) and save it to a profile in afterburner you can apply that profile when the pc boots up. This will help keep temps down nicely and can enable you to run a slower fan speed. I use -0.031v and -0.100mv AUX for stock clocks of 975/1250. I will report back tomorrow morning with the results.

Cheers Matt, appreciate it!

What is the expected performance loss at 1440p with undervolting? Not fussed about 1080p as the 290 will simply dominate anything thrown at it.

oweneades said:
At that sort of money I would be looking new.

Either this: 290 Tri-X

or, actually no, the 780 is not worth another £50 over the Tri X cooled 290.

If you can get a nice 780 around £350 then that would also be an option.

I wasn't going to pay that, I would have offered about £350, but still undecided. Not really looking for 3rd party coolers, ideally after reference to vent out the back allowing a dual card config later. May speak to the Parvum guys to get a mod for the base of my case allowing the addition of a 120mm fan to intake cold air

Geeman1979 · 17 Jun 2014 at 15:44

EVGA 780 SC on the MM for £400?

You can buy new for less with a free game.

http://www.overclockers.co.uk/showproduct.php?prodid=GX-218-EA&groupid=701&catid=1914&subcat=1341

LtMatt · 17 Jun 2014 at 15:45

snips86x said:
Cheers Matt, appreciate it!

What is the expected performance loss at 1440p with undervolting? Not fussed about 1080p as the 290 will simply dominate anything thrown at it.

Undervolting does not lower performance, it just gives the card less voltage. Less voltage = lower temps. Clocks remain the same as they do at stock. I can even overclock and undervolt my cards. I use the same voltage settings for 1050/1250 as i do for stock clocks. Any higher on core or memory and i need to up the voltage a fair bit. Note, you can only run -0.100mv AUX if you leave the memory at stock. Be careful not to apply overclock at startup in MSI afterburner. Otherwise you could have an unstable clock auto apply and you won't be able to stop it in time.

All my overclocks are tested using OCCT which has an error/artifact detector. It's great for checking core clocks.

oweneades · 17 Jun 2014 at 15:46

snips86x said:
Cheers Matt, appreciate it!

What is the expected performance loss at 1440p with undervolting? Not fussed about 1080p as the 290 will simply dominate anything thrown at it.

The trick with undervolting is to maintain the standard clocks whilst reducing the voltage. My 290X will happily run stock clocks (1000/5000) at -37mv for example.

As long as you keep temps below the throttle limit (94 degrees IIRC) then the clock speeds won't drop from the maximum boost level (947Mhz on the 290).

snips86x · 17 Jun 2014 at 15:47

oweneades said:
The trick with undervolting is to maintain the standard clocks whilst reducing the voltage. My 290X will happily run stock clocks (1000/5000) at -37mv.

As long as you keep temps below the throttle limit (94 degrees IIRC) then the clock speeds won't drop from the maximum boost level (947Mhz on the 290).

Ok - I think I will give it a try.

Matt - your tests would help greatly, thanks. Don't suppose you've got a download for your BIOS if I do grab a card do you?

Daftbrown · 17 Jun 2014 at 15:52

LtMatt said:
Negative, im running reference 290's.

Yeah, sorry... read the question wrong. That's what you get for running a small OCUK forum window in the corner of your screen when you should be working

There are definitely some running non-ref 290 Crossfire around these forums but can't quite remember who. Boomstick has put a couple in a new build if I recall correctly?

I'm dreaming of it... and if my World Cup betting doesn't fall flat on its face (big IF!)... I might make it a reality

thefogo · 17 Jun 2014 at 15:52

Boomstick already sold one due to heat issues I think.

oweneades · 17 Jun 2014 at 15:56

snips86x said:
Ok - I think I will give it a try, but your tests would help greatly. Don't suppose you've got a download for your BIOS if I do grab a card do you?

My card is a 290 which successfully unlocked into a 290X. I don't know if this might create issues if you tried to load the bios onto a stock reference 290.

All I did was run Afterburner and decrease the core voltage whilst checking stability. I would suggest trying this first on any 290 you might buy before flashing the bios (it may not be stable).

snips86x · 17 Jun 2014 at 15:57

oweneades said:
My card is a 290 which successfully unlocked into a 290X. I don't know if this might create issues if you tried to load the bios onto a stock reference 290.

All I did was run Afterburner and decrease the core voltage whilst checking stability. I would suggest trying this first on any 290 you might buy before flashing the bios (it may not be stable).

OK

Sorry, I didn't see who'd replied, I assumed it was Matt.

Same as above, should be working really

LtMatt · 17 Jun 2014 at 15:58

Using the default bios will be fine mate, no need to flash.

LtMatt · 17 Jun 2014 at 16:00

I've got some time now so will test for you now Snips. Can i put my case fans up to full speed like i would normally?

snips86x · 17 Jun 2014 at 16:31

LtMatt said:
I've got some time now so will test for you now Snips. Can i put my case fans up to full speed like i would normally?

Sure, I would do the same :cool:

LtMatt · 17 Jun 2014 at 16:49

snips86x said:
Sure, I would do the same

Wow what a pain in the arse. I have to reinstall the driver when i use different pci-e slots. I guess it's because the two lanes i was using were the PLX lanes. I tried to uninstall the driver, got an uninstall error yellow warning. Luckily i did a system restore safe point earlier. Turned the pc off, put the cards back in the correct slots, did the system restore, uninstalled drivers correctly, turned pc off, swapped cards around and now about to do the last part of the tests with the cards right next to each other lol. Lesson learned.

Here's the results with the cards two slots apart. It's a bit colder today so on a hotter day expect higher temps.

947/1250
-0.037v Core undervolt
-0.100mv AUX undervolt
Both cards set at 50% fan speed.
Two consecutive runs of Unigine Valley @1440P highest details.

LtMatt · 17 Jun 2014 at 17:12

Here's the results with the cards almost touching each other.

947/1250
-0.037v Core undervolt
-0.100mv AUX undervolt
Both cards set at 50% fan speed.
Two consecutive runs of Unigine Valley @1440P highest details.

The bottom card was fine, but right before the end the top card reached 94c and began to throttle a bit. 50% fan speed is not enough. 55-60% would be plenty though i'd have thought. If you can get any sort of space between the cards, it will help a lot. It should work though, just the top card will need a faster fan speed than the bottom one. My tip would be to find out which card is the cooler card and run that one in slot 1. Also change both cards paste for some high quality paste like Gelid or MX4 etc. If you can wedge something between the cards to create a forced gap, that will help. Finally you need some front intake fans with high static pressure, like mine. Gentle Typhoon 1850RPM's are ideal. They will force cold air in between the small gap between the cards.

snips86x · 17 Jun 2014 at 17:36

Nice one and thanks for your quick response.

I would safely say this has helped me greatly, once the seller gets back to me, I'll go for the reference 290. There will be no room between the cards if I try and crossfire, but a single card seems to give decent performance on a 1440p.

My assumption would be if I start to notice performance issues in 1440p, I'd add another one later on. From the noise tests I've seen I wouldn't want them anything over 70%, so your recommendation of 60-65% is great.

I have 2x120mm Zaward G3s in the front of my case which move about 95CFM. Not looking to change them yet, but if I do decide on the new EVOLV case, I will get some SP120s.

90 is not bad mate, especially when my MSI was getting close before I changed the paste. Now to buy the card **Excited**

LtMatt · 17 Jun 2014 at 17:37

snips86x said:
Nice one and thanks for your quick response.

I would safely say this has helped me greatly, once the seller gets back to me, I'll go for the reference 290. There will be no room between the cards if I try and crossfire, but a single card seems to give decent performance on a 1440p.

My assumption would be if I start to notice performance issues in 1440p, I'd add another one later on. From the noise tests I've seen I wouldn't want them anything over 70%, so your recommendation of 60-65% is great.

I have 2x120mm Zaward G3s in the front of my case which move about 95CFM. Not looking to change them yet, but if I do decide on the new EVOLV case, I will get some SP120s.

90 is not bad mate, especially when my MSI was getting close before I changed the paste. Now to buy the card **Excited**

If you just have one card then 50-55% fan speed will be plenty if you undervolt.

Forget CFM, it's all about static pressure mate.

I've compared high cfm case fans vs high static pressure fans. Static pressure won every time in temp tests. High CFM are useless unless the static pressure is also high. As soon as you put a filter over a high CFM fan it looses all its airflow but a high static pressure fan does not change it's airflow with a filter in front.

snips86x · 17 Jun 2014 at 17:52

Would give me an excuse to buy 2 of the Noctua Industial 3000rpm fans then

Their max static pressure is 7mm h2o!

LtMatt · 17 Jun 2014 at 17:55

snips86x said:
Would give me an excuse to buy 2 of the Noctua Industial 3000rpm fans then Their max static pressure is 7mm h2o!

I know it's absolutely nuts. I'm thinking about ditching my Gentle Typhoons for some. Problem is i'd need 4x120mm and 2x140mm and that's gonna be a big outlay just for a load of fans lol.

snips86x · 17 Jun 2014 at 17:59

LtMatt said:
I know it's absolutely nuts. I'm thinking about ditching my Gentle Typhoons for some. Problem is i'd need 4x120mm and 2x140mm and that's gonna be a big outlay just for a load of fans lol.

Tell me about it

Do you have a BIOS file for your 290, or is it just as simple as tweaking the profile and making sure it start on boot?