2 GPU's Or 1

thenightrider

Hi seen two gpu's Radeon HD 4850 512MB GDDR3 on adverts they are the 512 mb one's going to use them in sli how much better are these to 1 1gb 4850.
Would haveing 2 card's put it on par with a higher card or will this setup just give my gpu more memery?

BadCharlie

Well u cant SLI two ATI cards. You will need a crossfire Motherboard. So you should check out what you have before you buy anything.

I had 2x4850 in crossfire 512meg cards, and to tell the truth i found them very good. I prob should not have sold them on but im happy with what i have now.

512meg cards are fine i find for playing games up to Res 1680*1050. After that you do need video cards with more ram on them, like your on about the 1gig 4850.

So what screen res do you play at?
What motherboard do you have?
And its only worth getting the 4850 if the price is good. Could always look at getting the 5770, 4890 or 4870.... or Nvidia cards.
And whats your budget.

jonny72

thenightrider wrote: »

Hi seen two gpu's Radeon HD 4850 512MB GDDR3 on adverts they are the 512 mb one's going to use them in sli how much better are these to 1 1gb 4850.
Would haveing 2 card's put it on par with a higher card or will this setup just give my gpu more memery?

a 4850 with 1 gig memory is only slightly faster than a 4850 with 512.. most often you wouldnt notice the difference unless playing at very high res and even then.

Its a common misconception that double the memory is double performance.. its very very far from it

thenightrider

Im geting one of these motherboard's of adverts http://www.komplett.ie/k/ki.aspx?sku=352402 for 80 euro Ive got a 3Ghz dual core cpu going to overclock it and the 2 4850' s im geting for 100

Im prob going to play at around 1280 x 1024

What difference am i going to see by useing 2 card's compared to useing 1 card

Dublin_Gunner

At 12x10, Crossfire or SLI is a complete waste.

A €80 card of any description will play just about ANY game, maxed out at that resolution.

I would consider a better monitor first before you consider going dual GPU.

You should look at a few reviews of HD4850 in Crossfire. It does scale very well.

Here's a good one which should give you a rough indication of the performance boost you'll get - though please note the resolutions tested.

http://www.guru3d.com/article/radeon-hd-4850-and--4870-crossfirex-performance/4

And here's some VGA performance charts for current cards, including Crossfire setups.
http://www.guru3d.com/article/vga-charts-december-2009/

(use the 4870x2 as a rough comparison to 4850 crossfire at the resolutions tested)

BadCharlie

At that res all you would need is 1 4850 and it would do you fine. Should be able to play anything. But if you plan on upgrading your monitor in the near future then it might be worth getting the 2 cards. But as it stands now you only need 1 4850.

uberpixie

thenightrider wrote: »

Hi seen two gpu's Radeon HD 4850 512MB GDDR3 on adverts they are the 512 mb one's going to use them in sli how much better are these to 1 1gb 4850.
Would haveing 2 card's put it on par with a higher card or will this setup just give my gpu more memery?

In crossfire when using two cards, you do not get double the memory.

Eg. x2 512mb cards = 512mb of usable gfx memory. Half the memory is usable the same would be for x2 1gig cards = 1gig usable gfx memory.

This is the way sli/crossfire works: the contents of ram on each card must match, so you only get "half" the ram available.

Dublin_Gunner

uberpixie wrote: »

In crossfire when using two cards, you do not get double the memory.

Eg. x2 512mb cards = 512mb of usable gfx memory. Half the memory is usable the same would be for x2 1gig cards = 1gig usable gfx memory.

This is the way sli/crossfire works: the contents of ram on each card must match, so you only get "half" the ram available.

These days, not even the ram has to match - but you'll only ever be able to utilise a framebuffer equal to the smallest card.

i.e. you have a 512mb 4850 cf'd with a 1gb 4870, framebuffer will = 512mb.

Overheal

hmm. I was always under the assumption VRAM stored textures and vector data, instead of constantly trying to stream that over from the Mainboard RAM.

Dublin_Gunner

Overheal wrote: »

hmm. I was always under the assumption VRAM stored textures and vector data, instead of constantly trying to stream that over from the Mainboard RAM.

It does both, it stores data ready for processing by the GPU, and it stores the data ready to be output FROM the GPU.

thenightrider

So am i right in saying the only thing haveing 2 cards will do is let me play games at a higer Res will i be able to play games at a higer seting with 2 cards compared to 1 card i can prob get a hiher res from my moniter im not at home now and am useing the pc in college

Dublin_Gunner

thenightrider wrote: »

So am i right in saying the only thing haveing 2 cards will do is let me play games at a higer Res will i be able to play games at a higer seting with 2 cards compared to 1 card i can prob get a hiher res from my moniter im not at home now and am useing the pc in college

You'll have technically twice the processing power, so you should be able to play at higher resolutions, and with higher detail settings.

What size screen is your monitor at home? If its 19", its very unlikely it supports anything higher than 12x10. Or it could be widescreen, but thats probably 13x7 or so.

BadCharlie

thenightrider wrote: »

So am i right in saying the only thing haveing 2 cards will do is let me play games at a higer Res will i be able to play games at a higer seting with 2 cards compared to 1 card i can prob get a hiher res from my moniter im not at home now and am useing the pc in college

You dont need to crossfire if your playing at such a low res. And with only 1 4850 at the res you say your playing at. You will be able to play all the games with max detail settings. Crossfire will be such overkill.

roberthurley14

you really dont need that much power for youre resolution, i have a Nvidia gtx295 but i play at 1080 (full HD) at your res most basic cards should be fine

thenightrider

Ok i just found out my moniter will do 1680*1050 link http://www.amazon.com/Dell-E228WFP-Widescreen-1680x1050-resolution/dp/B001BKR5D8

I will also play on my 720p tv in my bedroom

Effluo

Out of interest what power supply do you have?

Also must agree that a 4850x2 would be just plain silly at that res

Dublin_Gunner

Neither are terribly stressful resolutions anyway, 720p being less than 12x10, 1680x1050 being not much more intensive.

Either way, a single HD4850 would be more than adequate.

Effluo

Dublin_Gunner wrote: »

1680x1050 being not much more intensive.

Well actually 1050 is the next best thing to full hd

Yes this does change your situation. Now the 2 4850's sounds like the better option. Important we know your psu though!

Dublin_Gunner

Effluo wrote: »

Well actually 1050 is the next best thing to full hd

Yes this does change your situation. Now the 2 4850's sounds like the better option. Important we know your psu though!

Eh, no its not. Full HD is 1920x1080 progressive

His screen goes up to 1620x1050, thats a fair bit off full HD.

I'd rather game at 16x12 tbh

thenightrider

I still need to get a new psu as i have a 620w no name power supply and maybe some better ram trying to do a build from second hand parts if i can save some money :P

What kind of power would i need for these

Effluo

Table half the way down dhows how 1050 is the next best thing to full hd
http://en.wikipedia.org/wiki/Display_resolution

But op if you need a new psu too the i'd disregard the the 4850x2 option as it is very power hungry and would lead to extra cost when getting the psu.

Hard to know what to get at your point. I'm kinda thinkin a 4870 512mb. They're pretty cheap and you could run your pc with it on a cx400 watt psu.

Op you probably could run a 4870 from your current psu, it would be inefficient but it prob would still work

BadCharlie

I don't trust no name PSU's had one blow on me before and i was lucky it did not take something out along with it.

If you will be playing at 1680*1050 then crossfire is a good option all right. Its what i had and it worked great. I turned off crossfire to see if i would notice and their was a big drop in FPS in most games.

2x4850 will use more power on idle + at full load then one card. While gaming i was using about 410watts but that was with an I7 which is 130watts on its own. So you should take all things into consideration before you buy.

PogMoThoin

My Corsair 750w psu went 2 weeks ago after only 18months, took the motherboard with it. I'm in the process of rma'ing it now. Suprised me, I've never heard of a Corsair blowing, just goes to show, I'd never trust a no name, but even with branded You're not safe. 7 yr warranty ftw, doesn't cover me for the mobo tho

Dublin_Gunner

I've always recommended Enermax PSU's, they have always served me well.

OCZ PSU's now are pretty damn good too, as they're built from PC Power & Cooling designs (OCZ bought them), and Fortron are good too.

Just read a couple of reviews, but anything around 600W should serve you pretty well unless you're doing uber high end stuff, like triple/quad GPU set-ups and highly overclocked Core i7's etc


Effluo - just give it up man! Steam users do not rule the world or invalidate maths! 16:9

Effluo

Dublin_Gunner wrote: »

I've always recommended Enermax PSU's, they have always served me well.

OCZ PSU's now are pretty damn good too, as they're built from PC Power & Cooling designs (OCZ bought them), and Fortron are good too.

At the price of Enermax's they'd want to last!

Also OCZ's are generally bad nowadays

Don't know anything of Fortron?

Dublin_Gunner wrote: »

Effluo - just give it up man! Steam users do not rule the world or invalidate maths! 16:9

I said 1050 is the next best thing to full hd. Is that not right?

Dublin_Gunner

Effluo wrote: »

At the price of Enermax's they'd want to last!

Also OCZ's are generally bad nowadays

Don't know anything of Fortron?



I said 1050 is the next best thing to full hd. Is that not right?

For a TV maybe, for a PC or gaming, 16x12 is better IMO (more pixels = more detail)

lmimmfn

PogMoThoin wrote: »

My Corsair 750w psu went 2 weeks ago after only 18months, took the motherboard with it. I'm in the process of rma'ing it now. Suprised me, I've never heard of a Corsair blowing, just goes to show, I'd never trust a no name, but even with branded You're not safe. 7 yr warranty ftw, doesn't cover me for the mobo tho

decent PSU should never take the mobo with it, id get onto Corsair. I had an FSP 600W blow on me 2 years ago, a big bang lol, didnt take anything with it though, unless it was a cheapy mobo? i had a 680i that i knocked over, would spark away if i tried to put any USB devices in the busted port but never blew.

Effluo

Dublin_Gunner wrote: »

For a TV maybe, for a PC or gaming, 16x12 is better IMO (more pixels = more detail)

I don't mean to go on about it, but is it not pretty agreed that a wider field of view is better for gamers?

It's more like our own vision and life-like, thus the benefit of having 2 or three monitors rather than just one big ass 32".

cherryghost

Effluo wrote: »

At the price of Enermax's they'd want to last!

Also OCZ's are generally bad nowadays

Don't know anything of Fortron?



I said 1050 is the next best thing to full hd. Is that not right?

Im using an OCZ 700w Stealthxtreme PSU for a while now, my Q6600 oc'ed to 3ghz, 8gb RAM, 4HDs, plenty of lights, and a gtx 295. Doesnt break a sweat

Skatedude

er, what operating system are you using? 32 or 64bit as if its 32 bit then you are limited to 4gb. that includes the video ram as well.

so if you end up with 2 by 1 gig video cards, that only leaves 2 for running windows

Dublin_Gunner

Skatedude wrote: »

er, what operating system are you using? 32 or 64bit as if its 32 bit then you are limited to 4gb. that includes the video ram as well.

so if you end up with 2 by 1 gig video cards, that only leaves 2 for running windows

While you certainly make a valid point, its a little flawed.

Only the vRAM of one card is seen by the OS, so only addressing of 1GB video ram is required, leaving 3GB of addressing space for everything else.

Not ideal, and you're right, when using cards with large framebuffers, a 64bit OS is preferable.

Effluo - it really depends on the games you're playing. Plus, a 16x12 screen can display widescreen resolutions no problem, 16x10 for instance.

Wider fields of view are restricted in some online games, as is offers those with widescreen monitors an advantage over those without.