Opinion on new graphics card

[rev_olie]

Hey,

I'm looking to upgrade my PC. I have been doing little bits over time and feel now its only lacking in RAM and my 9500GT graphics card.

I've now got an extra 2GB DDR2 RAM ordered and ready so my attention turns to the graphics. This is an area i have no real knowledge in so i was hoping someone my have an opinion.

I've got about £100 to spend and when i said that they immediatley said This Card an XFX HD 4870.

My worries are for that card:
My PSU
Heat.

I've got a Coolermaster Real power modular 520W PSU which had the required 6Pin graphics pci-e cables but has it got enough power to run this card and a Quad core 6600 Intel processor?

Also apparently its fairly hot? Anyone shed any light on that?

Thanks

 

[EXCellR8]

The XFX HD4870s are great cards, but you need to base your choices on what you mainly use your computer for. If you're looking to play the most GPU-intensive games, you want to aim for an enthusiast card (high-clock speeds, lots of onboard RAM etc...) but if you use the system for general computing, you don't need that power. As for the power supply, you need to find the amperage rating on the +12v rail(s) in order to figure out power requirements.

 

[rev_olie]

Thanks for the reply.

The PC is used for a wide variety of Jobs but everyday it usually has a game going. I'm mainly on Crisis or Call of Duty World at War and Modern Warfare.

As for the amperage, the unit reads 4 different 12V readings with 3x19A on the +12 and 1x 0.8A on the -12
Overall showing 480 overall on the 12v rail.

 

[EXCellR8]

well, if you have 19A on three +12v rails you have a total of 57A... which is more than enough for a single 4870/4890. you will notice a huge increase in performance while playing games, especially in Crysis where having a powerful GPU is essential. if you want to spend the money, i would recommend the 4870 as well. i have two and they have been remarkable for gaming. just make sure to bring the fan speed up from stock, or you may notice the card overheats during gameplay. the reference coolers can handle the heat, but you'll probably notice some performance hits if you don't bring the fan up to at least 50% under load.

 

[rev_olie]

Great thanks for clearing things up.

I'm going for the 4870 as somewhere I saw something about I think the 4880 not being much of an increase? Or maybe I'm getting mixed up...

 

[EXCellR8]

you're probably thinking of the 4890... which is slightly more powerful and features 1GB GDDR5. i would only recommend that card to someone with a large widescreen display or doesn't plan on using crossfire in the future. the single 4870 is fine and if the model you choose also has 1GB RAM then there is really no reason to go with the 4890.

 

[rev_olie]

Awesome well I've had to save up to get the one so i think 2 would be a bit OTT.

Thanks again

 

[Rage_3K_Moiz]

well, if you have 19A on three +12v rails you have a total of 57A

That is incorrect. If it were true, then you'd have 684W of power on the +12V rail alone!

Still the Cooler Master PSU should be fine; 40A on the +12V rail combined.

 

[rev_olie]

That is incorrect. If it were true, then you'd have 684W of power on the +12V rail alone!

Still the Cooler Master PSU should be fine; 40A on the +12V rail combined.

Just for curiosity and future reference how do you work it out?.

Do the 12V rail's not combine to give you 57A?
Also how come its listed as 3 12V rails, when there is only the one cable?

Its probably really obvious but may as well find out now.

 

[Rage_3K_Moiz]

The +12V rails are not additive; they are fed by the same transformer inside the PSU, and are actually virtual rails that are split off so as to keep potential power-hungry components like video cards and CPUs on separate rails. The 19A rating means that you can only pull a maximum of 19A from the rail, but you can only load one rail to 19A i.e. all rails cannot be loaded to maximum together. If this ever happens, it will trigger the OCP on the PSU and shut it down.

As for the +12V combined current rating, it's available here; I've linked to the image from Cooler Master's product page. There should also be a similar sticker on the PSU. Speaking of which, I think you meant 408W, not 480W, which would translate to 34A (Watts = Volts x Amps). Still sufficient for the 4870 though.

I hope that wasn't too confusing.

 

[rev_olie]

Ah i see now makes sense and yes i mean 408 big nasty typo

But its a good job you didn't say that 408 wasn't enough power because I've ordered it :haha:

 

[EXCellR8]

Well I'm confused then... this is why I only buy PSUs with a single rail, no math plz.

 

[Rage_3K_Moiz]

LOL mate, single-rail vs multi-rail is just marketing; there is no advantage of one over another. Besides which, most of the multi-rail PSUs out there just have a single +12V rail or source that is then split manually into separate rails with a fixed maximum current limit for compliance with the ATX12V 2.2 spec. The spec was originally designed with safety in mind, but there have been no hazards so far and so this is generally disregarded as being important.

 

[EXCellR8]

Makes sense... I usually go way overkill on PSUs anyways, so it's typically not an issue for me. When I bought this 1000W I looked at the +12 specs and it read 70A... said "that should be enough!" :haha:

 

[hellokitty[hk]]

LOL mate, single-rail vs multi-rail is just marketing; there is no advantage of one over another. Besides which, most of the multi-rail PSUs out there just have a single +12V rail or source that is then split manually into separate rails with a fixed maximum current limit for compliance with the ATX12V 2.2 spec. The spec was originally designed with safety in mind, but there have been no hazards so far and so this is generally disregarded as being important.

I like single rails, there are less cables...

 

[Rage_3K_Moiz]

LOL, I think you mean modular PSUs, which may or may not have multiple rails. There is no difference that I have seen in the number of wires from a single or multi-rail PSU.

Oh well, I'll shut up now. Electronics class is officially over! :wave:

 

[Ritwik7]

@ Sircuit : And why exactly are you spamming threads with your useless comments? I see in a number of them that you've had nothing to offer as far as advice is concerned.

That's funny...Sircuit's posts seem to have vanished!!!

 

[hellokitty[hk]]

LOL, I think you mean modular PSUs, which may or may not have multiple rails. There is no difference that I have seen in the number of wires from a single or multi-rail PSU.

I've never had a modular one yet (they have detachable cables yes?) but i've had one with 2 12v and one with 1 lol...