Wolygon

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Hello I am considering upgrading my lone HD 4830. My system is as follows:

Intel E7400
DFI LanParty - LT (DDR2 version)
Corsair Dominator 1066MHz
Antec Earthwatts 500W
HIS Radeon HD 4830 512MB
500GB Seagate 7200.12
Zalman CNPS9500
Thermaltake Armor MX+

21.5" LG Flatron 1920x1080

I was going to build a new i7 920 system but that has been halted as I cannot justify the cost at the moment. So instead I am going to put a little money into my current build. As well a a graphics card I shall be getting a new 1TB HDD and maybe a new cooler.

From what I understand 4830 x2 > 5770. Note that I am in Australia so prices are different. I can get a new HD 5770 for $185 or I can get a used 4850 1GB for like $70/$80. I know that the 4850 will be limited to the speed of the 4830, right?, but will the full 1GB of RAM on the 4850 be able to be used? Also would there be any performance increase if I got a HD 4870 1GB instead of the 4850? they go for about $100 used.

I was also wondering if my E7400 at stock speeds will bottleneck two 4830s, I am happy to run at 3.8GHz on my current cooler but 4.0GHz requires a lot more voltage and the temperature reaches 65'C on load which I'm not that happy with. Would 3.8GHz eliminate a bottleneck?

For the performance boost of an extra 4830 compared to the low cost, I'm guessing this is the best option though I am not to knowledgeable on crossfire systems. I know that they are considered worse then an equivalent single card system, but a 5770 is a lot more expensive.

Thanks for the help.
 
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As far as the power supply goes i would say it probably would run them as they (Antec) are a good make but the problem is a 4830 can be anything from 90 odd to 122 ish Amps depending on the chip and the board so trying to work out the actual draw is a bit tricky.
Personally i would give it a go but cant go as far as to recomend you do the same as it is a bit of a gamble. PSU calculators are in my experiance a bit hit and miss.
They do overstate the required power needed somewhat so on balance i would say if its got two PCIE cables on it then it should in theory run two cards. If it was generic i would say definatly dont but as its Antec then i wont go that far.
Sorry not to give a yes or no answer but it really is up to you on this...
There are lots of ifs and buts here. Crossfire support is a lot better than it used to be but you would still be at the mercy of driver updates and patches to ensure the cards worked properly with the latest releases. The performance is very good and from what i can see depending on the game played 2 X 4830 would be better than a single 5770 and sometimes by quite a way.
Don't know if you are aware but 2 X 512 mb cards dont actually give you 1gb of ram as both cards need to hold a copy of the same info, so you only have the same amount of Ram as if it was a single card.
Personally given the options i would go for a 4870 1gb card, for the sake of $20 i think its worth it. You can then either keep the 4830 as a spare (always handy) or sell it on to offset the cost.
Your other option is to wait the couple of weeks that its going to take for the new Nvidia cards to reach the shelves and see if it brings the 5 series cards down to a better price.

Mactronix
 

Wolygon

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A dual 4830 will stress your already aging 500watt PSU.
Is my PSU really a problem?

Don't know if you are aware but 2 X 512 mb cards dont actually give you 1gb of ram as both cards need to hold a copy of the same info, so you only have the same amount of Ram as if it was a single card.
No I didn't know that, thanks.

Personally given the options i would go for a 4870 1gb card, for the sake of $20 i think its worth it. You can then either keep the 4830 as a spare (always handy) or sell it on to offset the cost.
By this you mean to get a 4870 and don't crossfire it with the 4830, I would have a performance increase with the added 4830 right?

Your other option is to wait the couple of weeks that its going to take for the new Nvidia cards to reach the shelves and see if it brings the 5 series cards down to a better price.
I see this taking a while, especially in the mid-range as ATI wont have a competitor for a while I think.


 

Wolygon

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Ah ok, well thats not good. I figured that since the PSU has two 6 pin connectors it should be fine, I'm guessing it will still work good but it will be stressing the PSU too much...

EDIT: I did a PSU calculator and it reckoned only 350W if that means anything.
 
Not sure you can Crossfire a 4870 with a 4830 here is the compatibility chart and its not a recommended pairing http://ati.amd.com/technology/crossfire/charts.html
Also the higher card usually down clocks to match the lower card anyway so it would be just like getting a second 4830 anyway.

My recommendation is based on having the 1GB of memory which while not strictly needed will help with more demanding games at your res and the 4870 being a plain better/faster chip. Just seems the best price/perf option to me.

Mactronix
 

Wolygon

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I have looked around and it seems that you can Crossfire them. I'm thinking that ATI says it is not recommended because the faster card slows to the speed of the slower one.

My recommendation is based on having the 1GB of memory which while not strictly needed will help with more demanding games at your res and the 4870 being a plain better/faster chip. Just seems the best price/perf option to me.
Yes I could get the 4870 and run it by itself, but then I've got a spare 4830 which I could sell or use as a spare. However since Crossfired 4830s seem to out perform a single 4870 especially in games where Crossfire scales well (apparently outperforming the GTX280 by a fair bit). Maybe I should get the 4870 even if I'm Crossfiring, as later on I could get another 4870 and run them in Crossfire for more performance. What do you think about this?
 
Ok well here is a review that includes a 4870 1gb and 512mb http://www.techpowerup.com/reviews/HIS/HD_4870_IceQ4 I have left it on the Farcry 2 page because it shows the differance that there can be, other games dont show such a differance. Take a look through and decide what you think best.
My take on it would be to buy a 4870, sell on the 4830 now while its still worth having. In a years time people may not see it as worth having as better cards will be about for similar or less money and what you will get for it would be less.

As you say crossfired 4830's are a serious combo and if you plan to keep the 4830 even as a spare then it seems like trying it in CF with a 4870 has got to be worth trying. Given that crossfiring would require a PSU upgrade then i personally would stick with the single 4870.

As i said check the review and compare the performance between the 4830 and the 4870 to see if the increase is enough for you. If not then get another and crossfire, but the PSU upgrade really is recomended.

Mactronix
 

Wolygon

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The FarCry 2 difference in massive but most other games don't see all that much of a performance increase using 1GB, and I never liked FarCry 2 =].

Thanks for your help, looking at the benchmarks a single 4870 probably wouldn't benefit be a great deal but it seems like the easiest option for an upgrade. However I wouldn't mind Crossfiring two 4830s especially when looking at benchmarks.

Is a PSU upgrade too important to skip? The recommended PSU rating is 550W and I'm sure these have a lot of lee way as they need to take into account people running more powerful CPUs than mine, multiple HDD, etc. So I thought that even though mine is only 500W I should still be able to do it...

Also as I stated previously a PSU calculator only returned 350W, is this a wrong reading or is it not recommended to run that many watts on a 500W PSU which is only 70% of the rated power.

So is it not safe to run Crossfire 4830s on a 500W PSU with my build? What about just for like 6 months or something? I'm rather confused, if the PSU calculator is correct and my Crossfire system is only 350W, why am I unable to use this on a 500W PSU, does this much load really put too much stress on it?

Thanks.
 
As far as the power supply goes i would say it probably would run them as they (Antec) are a good make but the problem is a 4830 can be anything from 90 odd to 122 ish Amps depending on the chip and the board so trying to work out the actual draw is a bit tricky.
Personally i would give it a go but cant go as far as to recomend you do the same as it is a bit of a gamble. PSU calculators are in my experiance a bit hit and miss.
They do overstate the required power needed somewhat so on balance i would say if its got two PCIE cables on it then it should in theory run two cards. If it was generic i would say definatly dont but as its Antec then i wont go that far.
Sorry not to give a yes or no answer but it really is up to you on this one weigh up the pro's and con's and see what you decide.
it could run great or it could burn out a card or the psu or the whole PC, worst case scenario but i had to point it out.

Mactronix
 
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