Going from 460 SLI to 7850 or 270 CFX worth it?

[psolord]

Hey guys.

A friend of mine has a 2500k with two 460s, 256bit models, 1GB video ram, 1080p screen.

He is looking into a gpu upgrade path, that will not cost much, which will provide him with +50% processing power or more.

My personal recommendation was to look for a 7850 or 270 CFX solution. We can find the Asus Radeon HD7850 2GB DirectCU II V2 models for 130 euros each. GTX 660s which are also considered, are 155 euros each and 270s are 155 euros each also.

I used these reviews as my guides.

http://www.techpowerup.com/reviews/HIS/Radeon_HD_6850/28.html (this one because it has 460 and 6850 as equals)

http://www.techpowerup.com/reviews/MSI/HD_7850_Power_Edition/28.html (this one for comparing the 7850 to the 6850 which is the same as the 460)

http://www.techpowerup.com/reviews/ASUS/R9_270_Direct_Cu_II_OC/26.html (and this one for showing the 270 being 50% faster than the 6870, which in turn is already 15% faster than the 6850)

What are your thoughts on the subject?

Also I remember reading somewhere that GCN's CFX scaling was 10% more than SLI's. Is this true? Because if it is, for the 270 upgrade path, we could be seeing according to the above reviews:

+50% 270 over the 6870, +15% the 6870 over the 6850, +10% more scaling of GCN over GF104, overall 1.5*1.15*1.1=1.8975, ergo 90% more performance and in cases where framebuffer limitations come into play, significantly more. Similarly for the 660 upgrade path, possibly bar the 10% dual gpu scaling (dunno, maybe GK106s also benefit in scaling compared to GF104s?).

Are my calculations valid or am I completely off the track?

thanks

 

[bystander36]

It is not a good idea to go with SLI or CF unless you have to in order to get the results you want. 270 CF is not a good solution. Get a single r9 290 or GTX 780 instead. The FPS will be similar, but without any of the problems that go with SLI and CF. If that is too much, perhaps a 280x or 770. While 270 CF may have slightly higher FPS, those FPS are not delivered quite as smooth and some games do not support CF or SLI.

 

[Attic]

It is not a good idea to go with SLI or CF unless you have to in order to get the results you want. 270 CF is not a good solution. Get a single r9 290 or GTX 780 instead. The FPS will be similar, but without any of the problems that go with SLI and CF. If that is too much, perhaps a 280x or 770. While 270 CF may have slightly higher FPS, those FPS are not delivered quite as smooth and some games do not support CF or SLI.

I agree with this.

Generally get the fast single GPU you can afford, if you can afford the fastest single GPU and want more POWA, then go dual GPU at the top end.

If your bud wants to upgrade the 460 SLI, then i'd look for the best single card solution. A 780 or 290 w/ his 2500k would give him a solid performance and gameplay improvement over the 460sli. The 270 xfire would be a good improvement as well, but if the 780 or 290 is close in price I think the single gpu option will be better.

 

[blastingcap]

Only for the VRAM. Get out of 1GB or less VRAM setups while they still have value.

Better is to avoid multi-GPU altogether and get something like a R9 280X 3GB or higher. Keeping in mind that anything short of a 680/770/7950/7970/280X is not a big improvement over SLI 460 1GB's if you don't count VRAM... but the extra VRAM is very welcome.

 

[psolord]

Thanks for your replies guys.

If money was not an issue, I knew the solution already, lol. r9 290s cost 400 euros where we live, GTX 780 450 euros and r9 290Xs 500 euros. They are all out of the question.

The way I see it, two 270s will serve my friend well. He never had a problem with his two 460s and I've been using dual card setups, ever since the 4870X2.

Smooth framerate delivery is not an issue for us, because we game with vsync enabled. Worst case scenario, I enable MSI Afterburner's or RadeonPro's framerate limiter and the frames always end up 16.6ms long.

This whole frametime thing has been blown way out of proportion imho. It is much more important, to have a big performance pool to start with. A single card which reaches 75% the performance of a dual gpu solution, will never be able to be as smooth as two cards, especially in scenarios where the two cards can give solid 60fps with high gpu load and the single card, well, less than 60. I know that if the framerate drops below 60fps, it will be smoother on the single card, but we have already lost if the framerate drops below 60, so our goal is to keep it at exactly 60 in the first place.

In general, dual gpu solutions have the following advantages.

1) You can reach a single card's performance pool, with much less money. For example two 270s can easily give 780 performance and that's for 300 euros versus 450 euros. That's a joke. Moreover, the 150 euros you save now, you can add to the budget of the next cards you buy.

2) If one of the two cards breaks, you have the other to go by your business. If you have a single card, you may have to wait quite long for a replacement. Trade channels where we live, are not as fast as other countries and some shops have to send the cards abroad to get a replacement.

3) You have two HSFs to spread the heat, so you get less noise and possibly more overclocking potential. I know that more expensive cards come with greater quality HSFs, but they are not that better.

4) You can turn off one card if the game you are playing does not require the power of the second, thus saving power. You cannot turn off half the chip of a high end card.

5) When the time comes to sell them and get better hardware, it's easier to get rid of two cheap cards, to two persons, than get rid of one more expensive card, to one person.

Sure there's enhanced driver dependency, but the vast majority of games that are truly gpu heavy, will come with multi gpu support anyway and a driver will be soon available. We are not kids anyway with no patience.

So all in all, a single expensive gpu is out of the question. 300 euros is the limit. 270s seems to be the better choice.

In that regard, are my calculations of the initial post correct? Will two 270s give us a considerable performance jump over the 460s in SLI?

Thanks again.

 

[Attic]

If you are experienced and understand some of the considerations for running dual GPU then dual 270 will be up to 100% faster than the 460 sli. I don't know a worst case scenario, but i'd expect at minimum 50% faster.

Beyond that, if you are liking the 270's, then consider putting an OC on em because they are quite capable cards. I've used many of these and the only model I would recommend against is the sapphire dual x 270.

 

[Techhog]

Thanks for your replies guys.

If money was not an issue, I knew the solution already, lol. r9 290s cost 400 euros where we live, GTX 780 450 euros and r9 290Xs 500 euros. They are all out of the question.

The way I see it, two 270s will serve my friend well. He never had a problem with his two 460s and I've been using dual card setups, ever since the 4870X2.

Smooth framerate delivery is not an issue for us, because we game with vsync enabled. Worst case scenario, I enable MSI Afterburner's or RadeonPro's framerate limiter and the frames always end up 16.6ms long.

This whole frametime thing has been blown way out of proportion imho. It is much more important, to have a big performance pool to start with. A single card which reaches 75% the performance of a dual gpu solution, will never be able to be as smooth as two cards, especially in scenarios where the two cards can give solid 60fps with high gpu load and the single card, well, less than 60. I know that if the framerate drops below 60fps, it will be smoother on the single card, but we have already lost if the framerate drops below 60, so our goal is to keep it at exactly 60 in the first place.

In general, dual gpu solutions have the following advantages.

1) You can reach a single card's performance pool, with much less money. For example two 270s can easily give 780 performance and that's for 300 euros versus 450 euros. That's a joke. Moreover, the 150 euros you save now, you can add to the budget of the next cards you buy.

2) If one of the two cards breaks, you have the other to go by your business. If you have a single card, you may have to wait quite long for a replacement. Trade channels where we live, are not as fast as other countries and some shops have to send the cards abroad to get a replacement.

3) You have two HSFs to spread the heat, so you get less noise and possibly more overclocking potential. I know that more expensive cards come with greater quality HSFs, but they are not that better.

4) You can turn off one card if the game you are playing does not require the power of the second, thus saving power. You cannot turn off half the chip of a high end card.

5) When the time comes to sell them and get better hardware, it's easier to get rid of two cheap cards, to two persons, than get rid of one more expensive card, to one person.

Sure there's enhanced driver dependency, but the vast majority of games that are truly gpu heavy, will come with multi gpu support anyway and a driver will be soon available. We are not kids anyway with no patience.

So all in all, a single expensive gpu is out of the question. 300 euros is the limit. 270s seems to be the better choice.

In that regard, are my calculations of the initial post correct? Will two 270s give us a considerable performance jump over the 460s in SLI?

Thanks again.

How much are the 280X and the 770?

 

[bystander36]

Just recognize that there is a difference between 780/290 performance and 780/290 FPS. I realize most people view those phrases the same, but they are not the same. SLI/CF doesn't just have profile dependencies, they have microstutter, and more latency. It may be advisable to look at 7970/280x/770's instead.

And in the past, most SLI/CF complaints come with midranged GPU's. It's as if AMD and Nvidia do not spend the time to make their CF/SLI profiles work to their best with their midranged chips.

 

[Mondozei]

Better is to avoid multi-GPU altogether

Gotta admit that I giggled a little after I read that and then read your signature. Sure, I can see why you use multi-GPUs; you have to, with that kind of resolution, but still

Just recognize that there is a difference between 780/290 performance and 780/290 FPS. I realize most people view those phrases the same, but they are not the same. SLI/CF doesn't just have profile dependencies, they have microstutter, and more latency. It may be advisable to look at 7970/280x/770's instead.

And in the past, most SLI/CF complaints come with midranged GPU's. It's as if AMD and Nvidia do not spend the time to make their CF/SLI profiles work to their best with their midranged chips.

Quoted for truth. And the reason why AMD/Nvidia has typically been bad at midrange SLI/Xfire is because most people know by now that an expensive single GPU is better than two midrangers. Thus, the people who actually need SLI/Xfire are the kind of people with high resolutions, and by extention use high-end GPUs.

This all being said, SLI/Xfire has become better. A lot of this negativity is a lagging indicator, as economists like to talk, because(and this was especially the case with AMD drivers), framepacing was a big issue a few years back. People are relatively slow to reshape their opinions, but sure, a good single GPU will always be better if the advantage of the SLI/Xfire is not that great, but know that SLI/Xfire has gotten a lot better compared to just a few years ago.

My personal advice is to aim for a 770, it overclocks really nicely. A 290 would be great if you could get one. If you're looking at two 270X then it'd cost your friend 310 Euro according to your prices. I realize 90 euros isn't easy to just come by, but we're not talking 200-300 euros here. Maybe save a few months and get that 290 for 400 euros? Otherwise, I recommend getting a 770 and overclock it, Kepler is a very good architecture to OC. And if a 770 is out of the woods for some reason then I'd say get two 270X as the third option.

 

[Yuriman]

I'd like to point out that a single HD7970/280x is exactly twice a 7850/265, in terms of raw GPU power. If a 280x can be found for around the same price as a pair of 7850's, there is absolutely no reason to go with two cards.

 

[psolord]

If you are experienced and understand some of the considerations for running dual GPU then dual 270 will be up to 100% faster than the 460 sli. I don't know a worst case scenario, but i'd expect at minimum 50% faster.

Beyond that, if you are liking the 270's, then consider putting an OC on em because they are quite capable cards. I've used many of these and the only model I would recommend against is the sapphire dual x 270.

50% to 100% will be great. Thanks.

Just recognize that there is a difference between 780/290 performance and 780/290 FPS. I realize most people view those phrases the same, but they are not the same. SLI/CF doesn't just have profile dependencies, they have microstutter, and more latency. It may be advisable to look at 7970/280x/770's instead.

And in the past, most SLI/CF complaints come with midranged GPU's. It's as if AMD and Nvidia do not spend the time to make their CF/SLI profiles work to their best with their midranged chips.

I do recognize it. I just am of the opinion that 50% more money for the same performance with less stuttering is not worth it. Especially since I have the knowledge to keep frames at exactly 16.6ms.

How much are the 280X and the 770?

The 280X is 280 euros and the 770 is 290 euros.

 

[Techhog]

Then getting the 280X or 770 for a consistent boost in all cases makes more sense imo. Too many games that don't support CF release these days.

 

[psolord]

I'd like to point out that a single HD7970/280x is exactly twice a 7850/265, in terms of raw GPU power. If a 280x can be found for around the same price as a pair of 7850's, there is absolutely no reason to go with two cards.

In terms of shader core number yes it is the same.

But with two 7850s you have 2X32 rops and 1/3 more mem bandwidth if you run the memories at the same speed. It would be faster and cheaper than the 280x.

The performance gap would only increase with the 270s, since they have 25% more shader cores in cfx.

I know the scaling is not perfect in all games, but in most gpu limited scenarios it is admirable

Here's a review that includes 270X cfx, performance easily attainable from the 270s since they only have clock differences.
http://www.reviewstudio.net/868-amd-radeon-r9-270x-crossfirex-and-r9-280x-4-way-crossfirex-review

Certainly up there with the 780 and faster than the 280X.

The way I see it, good performance pool + good price + vsync = profit

 

[psolord]

Then getting the 280X or 770 for a consistent boost in all cases makes more sense imo. Too many games that don't support CF release these days.

There's a considerable performance pool that will be lost however, in games that do support dual gpu. 270 cfx can reach 780 performance levels, let alone 770. See above.

Can you give me some examples to see if the games that do not support dual gpu are in my friends list of interest?

 

[Techhog]

There's a considerable performance pool that will be lost however, in games that do support dual gpu. 270 cfx can reach 780 performance levels, let alone 770. See above.

Can you give me some examples to see if the games that do not support dual gpu are in my friends list of interest?

Considerable? It's less than 20% and should still beat the 50% minimum you want. If you overclock then it shrinks even more. If you're this adamant, though, just go get it.

 

[FalseChristian]

Only for the VRAM. Get out of 1GB or less VRAM setups while they still have value.

Better is to avoid multi-GPU altogether and get something like a R9 280X 3GB or higher. Keeping in mind that anything short of a 680/770/7950/7970/280X is not a big improvement over SLI 460 1GB's if you don't count VRAM... but the extra VRAM is very welcome.

You say avoid SLI/XFire altogether and yet you have a XFIre system?

 

[bystander36]

I fail to see why this thread was made. You clearly don't want to hear that none of us do not recommend it. If nothing we said would change your mind, then why bother with this thread.

I will leave you with one more thought to consider. You have mentioned a number of times how your expertise will compensate for the problems of CF, but you may be forgetting that YOU are not going to be using this system. When your friend has problems, it is going to be you that has to make it work right for him. Be sure you are prepared to support any issues he has.

 

[psolord]

Considerable? It's less than 20% and should still beat the 50% minimum you want. If you overclock then it shrinks even more. If you're this adamant, though, just go get it.

I fail to see why this thread was made. You clearly don't want to hear that none of us do not recommend it. If nothing we said would change your mind, then why bother with this thread.

I will leave you with one more thought to consider. You have mentioned a number of times how your expertise will compensate for the problems of CF, but you may be forgetting that YOU are not going to be using this system. When your friend has problems, it is going to be you that has to make it work right for him. Be sure you are prepared to support any issues he has.

I have grown to respect many Anandtech's forum members over the years and that's exactly the reason I started this thread here. So I can receive your arguments, which are well noted. I am not saying you are out of your minds.

I am just saying that there is a budget, from which I must try to get max performance. Also try to remember that both I and my friend, are already using dual gpu solutions with acceptable results.

I've learned what I wanted from this thread and it will be put to good use. Thank you all for your participation.

 

[Sinthoras]

Why does he even need that much power? One GTX 760 or R9 270X will do a perfect job on the 1080p resolution...
If he really needs more power after a year or so, he can just upgrade and buy a second one on SLI/CF.
But for now, the GTX 760 seems to be the perfect choice for gaming at 1080p.

 

[psolord]

He has taken a great interest on S3D gaming....! That's essentially 1920X1080X2. Even two 270s will not be enough, but with some correct settings he will be ok for the most part.

 

[bystander36]

He has taken a great interest on S3D gaming....! That's essentially 1920X1080X2. Even two 270s will not be enough, but with some correct settings he will be ok for the most part.

Make sure S3D gaming supports crossfire. It wasn't until 1-2 years ago that HD3D started to support crossfire. S3D might not even support crossfire.

At that point, I'd ask your friend. Find out what he is willing to live with or try. Maybe have him read this thread. He might not feel the same way you do.

 

[blastingcap]

You say avoid SLI/XFire altogether and yet you have a XFIre system?

To you and the other guy who said the same thing already in this thread: ever consider why a multi-GPU user may warn others from going down the same path?

I have always warned against multi-GPU for games due to microstuttering, and you can see even with frame pacing that multi-GPU rigs have higher frame latency differences from frame to frame (see, e.g., the latest Anandtech review of the 295X2). This is true for CF and SLI.

Some games do not even partially support multi-GPU configs.

It gets hot and loud running multi-GPU configs.

In fact, I actually broke up my R9 290 CF setup recently and am going with a solo R9 290 with the other going into my gf's computer. Just did not change sig block yet.

 

[psolord]

Make sure S3D gaming supports crossfire. It wasn't until 1-2 years ago that HD3D started to support crossfire. S3D might not even support crossfire.

At that point, I'd ask your friend. Find out what he is willing to live with or try. Maybe have him read this thread. He might not feel the same way you do.

Thanks for the warning, but we have been using tridef for quite a while and it has no problem with dual gpu. Here's some screen caps from Thief.







Also for anyone that wants a taste of how smooth gameplay really is with dual gpu, here's a short 60fps clip I made with fraps.

http://www.multiupload.nl/2RV4PG2JFK

Pay special attention to the beginning and end of the clip, where I recorded a lot of camera panning, specifically to show how smooth framerate is. Fraps does not help for the rest of the clip. My poor 2500 had to cope with providing the cards with twice the frames and also capturing the whole thing to hdd. Without fraps, it's 60fps steady throughout. Also it is the same for most games in which the system can keep a steady 60fps. For those that it can't, it's a lost cause anyway and a single gpu wouldn't help. It would actually produce less framerate.

If you want to play the clip in 3D mode, you can play it with any playback medium, just set your display to top/bottom 3D, but people into this stuff already know that I guess.

Now tell me, in cases that the gpu load hits 80% or more for both cards, in order to keep 60fps, what kind of single card should I have, to be able to render a steady 60fps and in this regard, how is dual gpu bad? The same goes in the 270 CFX solution vs a single gpu, in comparison of how much each solution would cost.

 

[bystander36]

When you say S3D, I guess you were talking about HD3D. That's AMD's version of stereoscopic 3D. I'm a big fan of 3D Vision, which is Nvidia's version of stereoscopic 3D.

A lot of us have Crossfire and SLI setups. We are well versed on how they perform. I personally have 680 SLI. While SLI is pretty decent, I'd definitely trade it in for a single 780ti, even if 680 SLI has more FPS. Some games run better than others in SLI, the same with Crossfire. I previously had 6950 CF.

I believe SLI and CF are only worth it when you are getting ~40-50% more FPS than the single card option. When I got my setup, there was no single card option. I also would not figure a Titan into that equation, as that is priced beyond reason.

 

[TreVader]

BTC tanked today, you might see some pretty desperate people on ebay. Check around, many to be had for <350 and some for 300 ish. And it's only going to get better over the next few days as people realize what a hole they put themselves in.



A 290 will perform just as well as 270CF but without the issues of CFX.