Crossfire scaling for 2 HD 4890s in CF on 27in monitor @ (1920x1080)

Neither (sort of)

GPU architecture and drivers, and how demanding the graphics are, are what's important.

That would fall more onto the resolution thing, more pixels = more demanding, but so is DX11 and anti aliasing. Physical size is 100% irrelevant.

The 4000 series doesn't scale near as well as new GPUs, but it should attain 60-80% scaling. My 5850s get around 70-90, while the 7000 series are showing up to 100% scaling.

Forgive my ignorance but, what does 60%-80% scaling mean technically speaking?

Well if you got 100 frames per second on 1 card, it would be 160 to 180 on two cards.

But I think your question is more about what sort of performance hit you'll see at 1080p compared to 1440x900. Honestly, it will be pretty big. You will definitely have to reduce most game settings, and possibly lose AA altogether. Still, a nice big 1080p screen makes up for it until you can maybe upgrade you GPU.

I do advise against getting a 27" 1080p screen, just because most people sit maybe 3-4 feet away from the monitor, and the pixels get pretty big (as in, a low pixel-per-inch count) so the image won't look as sharp. For example a 22" 1080p screen would have a super high pixel density (high pixel-per-inch count) which makes the image look a lot sharper. I use a 24" and it is really nice. I'd suggest if you want to go 27", go view some that size in person first.

I have and I find the 27in to be quite fitting to my taste. My main concern is how 2 HD 4890s in crossfire would perform on a monitor of that size and resolution. I'm in no way surprised that I would get hiccups with one Hd 4890 on a monitor like that, but with CF I would hope that I would have some bit of improvement.

By the way, thank you for the advice, I truly appreciate it and I will be considering it when looking further into this.

4890 CF should be somewhere in the neighborhood of a GTX 580 performance perhaps a bit less.

close to a 480,but not a 580.

Do you think that 2 HD 4890s in crossfire would handle a 27inch monitor @ 1920x1080 well on say a game like Crysis ?

Yes, and just so you are aware, the size of the monitor has no baring on how it'll perform. A 15" 1080p monitor takes the same power as a 52" 1080p TV would.

Be aware, that 4890's do not support DX11, so games of that nature will allow you to max out the graphics as you'll be forced to use the alternative graphics versions of those types of games.

I'd also like to add that 27" at 1080p is quite sharp and clear. I see no reason why you would want to avoid it. It might not be as clear as these 2500x1600 monitors give, but I can't imagine that I would care with as clear as it is already and lower resolutions allow for smoother game play.

Yes, I'm aware that they don't support Dx11 and I'm ok with that. This was my first major pc build and I have no problem waiting to get a dx11 card down the road. How do you think Crysis 2 or Prey 2 (both on max settings without dx11 of course) would perform with the specs of my pc (on a 27in 1920x 1080) monitor?

nope close to GTX 580 performance would be 4890CF

People have continued to say it would handle it. I'm not sure why you keep asking.

I asked a more specific question. You should be aware that the graphical demands of games differ and I wanted a coherent answer regarding Crysis 2 specifically. I asked this question because it is one of the more demanding games and if my setup would run it fine then I would have no worries about other games. Given that their requirements may be somewhat lower than C2.

Crysis 2 without DX11 is not a demanding game. It will be easy to handle. I play Crysis 2 in 3D with two 470's and I am pinned at 60 FPS in Dx9 with v-sync on (in 3D it generates 2 frames for every frame, so it would likely get 100+ FPS in normal 1080p mode).

Thank you for the coherent response. I appreciate the input guys. I'll be purchasing my monitor this weekend ;D . I'm also getting the Fractal Design XL black pearl case.

sry,but you need to recheck,4890 crossfire is close to a single 480,not a 580.2-5850's in crossfire barely compete with a 580.

here's a good chart for some gpu comparisons:

http://www.anandtech.com/bench/Product/301?vs=300

two 460s are a bit faster than a 580 and a 4890 is as fast as a 460 but personal opinion and games come into play TWIMTBP titles naturally run better on a lesser powerful Nvidia card of course. That link you posted is 5870/6870cf but the 4890 is comparable to gtx 460 performance. http://www.hwcompare.com/8281/geforce-gtx-460-1gb-vs-ra...

the link i posted was just that,A link,the5870/6870 just happened to be on there,you can change them yourself.

but you also have to put into account that the 460 is also newer(dx11) and will scale better than 4890's in crossfire.(depending on resolutions of course)
I do understand your point,unfortunatly with so many variables in the equation,I doubt we both could get an exact comparison due the differences in technology of the cards and the testing done by different review sites being inconsistent.


as for the OP's question:
from what i have been reading though,the 4890's in crossfire will only perform best in 19200x1080(1200) and higher resolutions,lower than that and they dont scale well at all.

I love a good civil debate,i get to learn as much as everyone else.Ty gamerdude

4890 is same speed as GTX 460 and scalability in CF/SLI is on a per game per driver basis just like in single mode. They are perfectly competitive with each other in CF and SLI respectively as well with the GTX 580 why cant the fan boys just admit Radeon makes good cards and has been for a long while me I like both camps personal cause being biased is stupid and stupidity costs to much money.

Fanboy?I try and be polite and you call me a fanboy?FYI..I have been running ati for years,and still do,I do my research before I open my mouth,you should do the same.i have been running crossfire since the 3870's,4870's,5850's,5870's and now 6950's,so I do know how they scale.My first card ever was an nvidia.i could care less who makes them,i buy whats best for my money at the time of purchase.
radeon doesnt make cards,AMD makes gpu's,manufacturers make the cards.

I wasn't talking about you silly I was talking about the many Nvidia biased bigots and how they exalt every GTX card is better than there Radeon HD counterpart then they traditional go on to spout biased rhetoric and marketing catch phrases like Cuda and Physx and Unigen Nvidia benchmarks and tweaked to improve only Nvidias games and hold back Radeon architecture and such LOL. PS Radeon is still Ati just with a shortened name Radeon makes the Cards AMD just owns the rights to the Radeon brand.

ah,well then.I agree with you  

It would have been nice if you two (Earnie and Gamer Dude) would have not wasted my time with biased bickering, but ultimately I got a little insight from it. Thank you. My last question is this.

Does crossfire scaling for HD 4890s perform better at higher resolutions like (1920x1080) or at lower resolutions like (1680x1050) ? If so, why?

p.s. I know someone mentioned earlier that the cards scale better at higher res. but I would prefer a coherent answer as to why. Thanks again for the insight guys.

Scaling is the same at all resolutions, BUT at lower resolutions, you will often get bottlenecked by your CPU limiting how many frames that can be produced.

It's not that the graphics cards are scaling worse at low resolution, it's just that the CPU holds back performance once you reach a so many FPS.

I owned CF 4890 from Aug 09 and all of 10 and I used them to drive a 1080 Sony Bravia 42" T.V and they where beast more power than a GTX 480 so ya if they are beast @ 1080p driving a 42" big screen they will be even more powerful @ 1050 22' monitor res.

Thank you for the concise answer sir. I appreciate the input. So all in all, would you say it's safe to say that I would have no problem whatsoever running HD 4890 cf config on a 27in 1920x1080 monitor for more demanding games?

4890CF is more power than a GTX 570 so ya you will run any game maxed @1080P with 4890CF

Sounds good. I'm also purchasing a new case tonight. I'm looking at the Fractal Design XL cases. Should I go with Gun-metal grey or flat Black color scheme????

Just make sure you get a case with real good airflow the 4890CF run VERY VERY hot !! so good air flow is a must. Fractal makes great cases from what I have seen of them limited albeit and color is subjective towards your own opinion and taste I like them both but would take the black one first.

My 4890s run at a solid 37c idle and 47c-50c under load. Is that sound like a good temperature area?

Yup that's good temps when I had my 4890s in CF I had an at the time a run of the mill smaller mid tower case that I picked up for $50 locally at Memory Express which is a Western Canada Computer store chain like Microcenter. It was a top mounted PSU old school style and the bottom 4890 was less than an 1/8 of an inch from the bottom of the case that had absolutely no ventilation holes or nothin and as well it made the fan louder than a hair blow dryer when under gaming load LOL not joking temps in excess of over 100c under gaming load and it heated up my apartment in the Summer like no other I was sweating bullets. PS what brands of Radeon HD 4890s do you have I had 1 Sapphire and one XFX and they where both loud and hot as heck but they were great I wish I had then today.

I wish I had awesome Canadian computer stores like NCIX or Memory Express. I use a Gigabyte HD 4890 and a Diamond HD 4890. They run wonderfully. I bought them about 3 months ago (slightly used) off eBay. I wish companies like AMD and NVIDIA wouldn't discontinue cards like these so quickly, they really do perform well and become reasonably priced. I bought them because I just couldn't afford a high end HD 5000 or 6000 series card at the time. I will upgrade in the future though.

4890CF is still a high end setup like I say I wish I still had mine but I had to move away for work so I sold my PC and I now run a single GTX 275 errr that I got a good deal used last summer only paid $80 so its alright same performance as 4890 so it is decent. 4890CF will run BF3 and Crysis 2 maxed out ultra 1080P @ a solid 60fps what more do ya need really. PS ya Memory express is so fun to shop at it is like a toy store for grown up kids LOL.

Thank you for the info, I look forward to getting my new 27in monitor. Hopefully everything performs well.

Ok, so I recieved my Asus Ve278q monitor today, free of scratches, dings and dents. Turned it on and VWAHLA! no dead pixles or high pitched whining. I tested crysis and skyrim on max settings (without dx11) and everything is soo smooth and colorful. I havent even messed with the the color settings or anything. Im happy with my choice. Its such a huge beast of a monitor.   Thank you all for the advice.

Good to hear it! Now you can look down on console peasants with even more superiority  

Indeed. I get my new Computer Case tomorrow (Fractal Design XL Black Pearl) so Ill be gettin all my parts over to that case. Im really excited about it. Its just nice to finally have this monitor. Its sooo immersive. Eventually, I may get 2 more (when they go down in price) for Eyefinity. By then I should have a new GPU but Im happy with these for now. Now, what Im really looking forward to is running Prey 2 on this rig. Im dying to have that game. Does anyone know if it will be running on DX11? System requirements?

I wasnt talking about Prey1 running on DX11. Im talking about the upcomming title, Prey 2. I hope the game runs well on the modified IdTech 4 engine.

Yeah, that makes me happy knowing that it will look great and meet decent requirements. PREY 2 FTW!

It might look good... Rage had a lot of issues at launch. Looked alright and all, but definitely had issues.