512mb 4770 Xfired or 1GB 4850x2?

[Shedlife]

Dual 512mb 4770s or a 1GB 4850x2

I'll be playing at 1680x1050 all game settings on full graphic settings, like Crysis, Fallout 3, Call of duty (X).

I just can't decide. Both around £150 and have seen no benchmarks at all comparing the two, when I thought it would be an obvious point of interest!

[CAT-THE-FIFTH]

The HD4770 crossfire would be my choice as it should consume less power at load. However the HD4850X2 maybe faster as it has more stream processors. IMHO,it maybe worth looking at an HD4890 too.

[Shedlife]

Well the main thing is the 1GB memory vs 512mb, as that 512mb memory in the 4770 seems to always let it down when playing with full AA and at high res!

[CAT-THE-FIFTH]

My 8400GS consumes even less power under-load, yet you wouldn't buy one lol

The HD4850X2 consumes more power and hence produces more heat. This means the card will be noisier too. AFAIK the HD4850X2 is one noisy card.

The 1gb RAM on the HD4850X2 is actually 512mb per RV700 GPU.The RAM is not shared and hence games will only "see" 512mb of RAM. The main advantage like I said before is the increased number of stream processors the HD4850X2 has. However the HD4770 is clocked much higher and seems to have a decent overclocking headroom for the GPU from what I have read.

[Pulseammo]

Well the main thing is the 1GB memory vs 512mb, as that 512mb memory in the 4770 seems to always let it down when playing with full AA and at high res!

Id take the 4850x2 for the reason of the ram. If you ever upgrade to a 24" monitor the ram will set it in better stead. It may also be a bit more future proof if there is such a thing as games start to take up more RAM. I guess if you play GTA4 now you'd get a big boost too, but really it prolly only eats ram because it may be a bad port .

Basically if you plan to keep the card for a good while then go with the ram over the power consumption and heat imo.

[Shedlife]

Sorry I should of said, its 1GB per GPU so effectively a 2GB 4850x2

http://www.scan.co.uk/Products/1GB-S...-4x-DVI-I-HDTV

The 4770s would fall back due to there 512mb of memory, I just can't decide and there is no benchmarks at all

[Will404]

Id take the 4850x2 for the reason of the ram. If you ever upgrade to a 24" monitor the ram will set it in better stead. It may also be a bit more future proof if there is such a thing as games start to take up more RAM. I guess if you play GTA4 now you'd get a big boost too, but really it prolly only eats ram because it may be a bad port .

Basically if you plan to keep the card for a good while then go with the ram over the power consumption and heat imo.

AFANK he meant 2*512Mb HD4770's, which == 1GB overall, or 1*4580X2 1Gb, which has 512Mb memory per GPU, therefore a total of 1GB. So they both have same memory

[CAT-THE-FIFTH]

Sorry I should of said, its 1GB per GPU so effectively a 2GB 4850x2

http://www.scan.co.uk/Products/1GB-S...-4x-DVI-I-HDTV

The 4770s would fall back due to there 512mb of memory, I just can't decide and there is no benchmarks at all

That is the 1 gb HD4850X2 meaning that there is 512mb of RAM per GPU.

This is the 2gb model:

http://www.scan.co.uk/Products/2GB-S...DVI-I-x-4-HDMI

It has 1gb of RAM per GPU.

The X2 cards do not share RAM. Hence a 1gb X2 card has 512mb per GPU and a 2gb card has 1gb of RAM per GPU. The games will see 512mb and 1gb of RAM respectively.

The X2 cards are basically crossfire without the motherboard and hence the same rules apply.

If you are going for a 2gb HD4850X2 it is better IMHO. However for the same price a superclocked HD4890 will also be a good option as these challenge even a GTX285 at times and there are none of the disadvantages which crossfire setups have.

[Pulseammo]

Seems that scan have made an error in the description for the card that the OP linked. You guys are right though, the one he has linked has to be the 512mb x2 version.

[Shedlife]

Ahhhh well that changes everything now then and makes me EVEN more stuck

[CAT-THE-FIFTH]

Look at these HD4770 crossfire reviews:

http://en.expreview.com/2009/04/28/f...benchmark.html

http://www.tomshardware.com/reviews/...fire,2288.html

http://www.legitreviews.com/article/966/1/

http://www.elitebastards.com/cms/ind...=714&Itemid=27

http://www.legionhardware.com/document.php?id=828

When the scaling is good performance looks very impressive. However an HD4890 is also still a very good choice especially the superclocked ones running at 950mhz+ as these can challenge a GTX280 or GTX285 IIRC. The HD4890 has a lower number of stream processors than an HD4850X2 or HD4770 crossfire setup but has more RAM,more memory bandwidth and a faster clock-speed to compensate.

[Pob255]

At a res of 1680x1050 512mb is fine there's little benefit going for 1gb, it's when you go up to 1920x1200 or 2650x1600 that the extra starts to have real meaning.

As your motherboard (asus M3A79-T Deluxe) can run 2x16 pci-e it makes the choise hard.
persoanlly I'd be slightly more tempted by two 4770 in crossfire

[Shedlife]

Huh, dual 4770s would have a higher bandwidth than a 4890 when overclocked

[holy god of nil]

I would have thought a single card solution, whatever it is, would be most versatile as in a while you could pop another one in to crossfire? This is obviously not possible with 2 4770's.

[CAT-THE-FIFTH]

Huh, dual 4770s would have a higher bandwidth than a 4890 when overclocked

The HD4890 has 256bit memory access for the GDDR5 whereas the HD4770 has 128bit access and hence at the same RAM speed each GPU will half the bandwidth of an HD4890.

[Shedlife]

I thought dual 4770s will have the same bandwidth as its 2 x 128bit, and they can overclock that memory to around 4600Mhz? Which is a bandwidth of 147.2 GB/sec