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Hey guys,

I cannot find any reliable review comparing 4GB and 8GB performance of rx 480. I vaguely recall some review that had that and the difference was quite bigger then I expected (well, I mostly expected no difference), but I can't find it anymore.

I suspect the difference might be bigger for higher resolutions, but I'd like to see detailed numbers. Any links?

Thanks.

Anandtech has a comparison, the difference is only a few percent.

http://www.anandtech.com/show/10446/the-amd-radeon-rx-480-preview/4

Ryan Smith at AnandTech did a small preview which includes benchmarks for both 4 and 8 GB variants. 4 GB versions have an effective memory bandwidth rate of 7 Gbps with 8 GB versions having 8 Gbps. In some cases the differences will be negligible, others significant.

Edit: Someone beat me to it.

I would think the performance difference would be similar to what you would find with any other card that comes with a 4GB and 8GB option. At present, I don't think there is any scenario where 8GB offers any appeciable improvement over 4GB, even at 4K resolutions. But people are constantly talking about "the future".

It is likely that 4GB is plenty of RAM. But, if you have a 4K monitor, or if you plan to use the card for more than 2-3 years, it would be worth getting the 8GB model "just in case".

I don't think anyone interested in cards at this level ever got hurt by having more video RAM than they needed.

If you are actually in Polaris's intended market of 1080p resolutions, then 4GB ought to be fine.

2560x1440... probably OK too, at least in as much as the 8GB version of the same card isn't going to be massively faster.

4K? Don't buy this card because you either don't care about 3D support (and can use a cheaper & much cooler solution) or you want something beefier and you've already shelled out for a 4K display, so don't stop now.

There are always scenarios like this http://www.tweaktown.com/news/52122/dooms-nightmare-graphics-setting-requires-insane-5gb-vram/index.html.
Which is a bit extreme at this point.
But these are not http://www.tweaktown.com/tweakipedia/90/much-vram-need-1080p-1440p-4k-aa-enabled/index.html
So in most cases 4GB of VRAM is enough for everyone.

Thanks, that's what I was looking for.

It seems that 4GB might have much worse stuttering in some scenarios (well, specifically in GTA at 2560x1440, but that is also the only graph they showed with 99th percentile FPS and not overall average).

I've been out of the loop for so long that when I bought my GTX950 I was thinking "oooh, 2GB VRAM! Nice!"

Silly me. DOOM has already shown me the error of my ways. And that's on my lowly 1080p monitor. The 32" 1440p screen comes in this week. I already know I'm gonna need bigger guns.

I guess 4 is the new 2 these days.

I've been out of the loop for so long that when I bought my GTX950 I was thinking "oooh, 2GB VRAM! Nice!"

Silly me. DOOM has already shown me the error of my ways. And that's on my lowly 1080p monitor. The 32" 1440p screen comes in this week. I already know I'm gonna need bigger guns.

I guess 4 is the new 2 these days.

The issue with 950 running DOOM is not the VRAM, it is the GPU itself. It isn't much above the minimum system requirements, so even if it had 16GB it would still be an issue.

xeridea wrote:

I've been out of the loop for so long that when I bought my GTX950 I was thinking "oooh, 2GB VRAM! Nice!"

Silly me. DOOM has already shown me the error of my ways. And that's on my lowly 1080p monitor. The 32" 1440p screen comes in this week. I already know I'm gonna need bigger guns.

I guess 4 is the new 2 these days.

The issue with 950 running DOOM is not the VRAM, it is the GPU itself. It isn't much above the minimum system requirements, so even if it had 16GB it would still be an issue.

This. GTX 950 << GTX 670 ,which is the minimum for Doom. (By the numbers, it's a little better in GP/s but way worse in GT/s, GFLOP/s and GB/s, which is unsurprising as it's on the same process but 3/4 of the size and with half the TDP...)

GTX 970 4 GB or R9 290 4 GB is recommended, so xeridea if you're looking for a BFG that's a bar to aim for. TechPowerUp's performance summary chart from its RX 480 review might also help you quickly get back in the loop.

xeridea wrote:

I've been out of the loop for so long that when I bought my GTX950 I was thinking "oooh, 2GB VRAM! Nice!"

Silly me. DOOM has already shown me the error of my ways. And that's on my lowly 1080p monitor. The 32" 1440p screen comes in this week. I already know I'm gonna need bigger guns.

I guess 4 is the new 2 these days.

The issue with 950 running DOOM is not the VRAM, it is the GPU itself. It isn't much above the minimum system requirements, so even if it had 16GB it would still be an issue.

I used to build/upgrade so frequently that I never had issues before. I just haven't kept up with the graphics war like I once did. I'm still in the refund window so I'm returning it. Do you think a 4GB GTX960 would be adequate for 2560x1440 or should I plunk down for a 970? I almost never buy new games, but I wanted DOOM for my birthday. It'll probably be the most taxing thing I play for the next 2 or 3 years, so I'm honestly basing my decision around that one game.

kvndoom wrote:

I used to build/upgrade so frequently that I never had issues before. I just haven't kept up with the graphics war like I once did. I'm still in the refund window so I'm returning it. Do you think a 4GB GTX960 would be adequate for 2560x1440 or should I plunk down for a 970? I almost never buy new games, but I wanted DOOM for my birthday. It'll probably be the most taxing thing I play for the next 2 or 3 years, so I'm honestly basing my decision around that one game.

GTX 970 is not necessarily going to be great at 2560x1440 in Doom, I'd be looking at GTX 980 Ti or GTX 1070 level cards.

Well as someone with a 1440p monitor, a GTX 970, and been playing DOOM every day since I bought it (few days ago when it went on sale)... it will comfortably do "High" settings with things like AA off but not "Ultra." Though personally I find recommending a GTX 970 right now very hard given the GTX 1060 almost certainly shipping in mid July and sounds like it would fit all your needs. But it also sucks to not play your game you've been looking forward to (and DOOM is *excellent* IMO).

Topinio wrote:

xeridea wrote:

I've been out of the loop for so long that when I bought my GTX950 I was thinking "oooh, 2GB VRAM! Nice!"

Silly me. DOOM has already shown me the error of my ways. And that's on my lowly 1080p monitor. The 32" 1440p screen comes in this week. I already know I'm gonna need bigger guns.

I guess 4 is the new 2 these days.

The issue with 950 running DOOM is not the VRAM, it is the GPU itself. It isn't much above the minimum system requirements, so even if it had 16GB it would still be an issue.

This. GTX 950 << GTX 670 ,which is the minimum for Doom. (By the numbers, it's a little better in GP/s but way worse in GT/s, GFLOP/s and GB/s, which is unsurprising as it's on the same process but 3/4 of the size and with half the TDP...)

GTX 970 4 GB or R9 290 4 GB is recommended, so xeridea if you're looking for a BFG that's a bar to aim for. TechPowerUp's performance summary chart from its RX 480 review might also help you quickly get back in the loop.

The minimum real-world spec for Doom at around 60 fps is south of the 670; two friends of mine with 660s have enjoyed the hell out of it at 720p at around 60 fps. For whatever it's worth, I've even gotten it running in ugly but fun fashion on a Radeon 7750. If memory serves, the 950's just a nudge faster than the Radeon R7 370 in my home theater PC for Doom, and that manages 1600x900 on medium without a hitch, and is still enjoyably spry with high detail settings enabled. I do wonder what difference Vulkan will make when the time comes.

Back to the other concerns: Doom loves video memory at higher settings, especially for the higher-end antialiasing options (TSSAA 8x eats RAM like buttered popcorn) and Nightmare-quality graphics options, which require at least 5 gigs of video RAM to run stably. Don't expect other upcoming AAA titles to be shy about wanting video memory either. The 8 gig RX 480 will be a much better forward-looking investment, even if the performance delta amounts to around 5-8% when you're staying within 4 gigs of RAM.

I played the closed alpha and closed beta and the open beta, and the FPS was quite variable -- so for card shopping, when looking at average FPS from reviews I'd be looking quite a bit higher than 60. OC3D shows this. Guru3D has a chart of averages per card, I wasn't super happy with my R9 290X's performance so am suggesting a bump to the next tier of performance cards there. Ultra is where it's at IMO

Concupiscence wrote:

The minimum real-world spec for Doom at around 60 fps is south of the 670; two friends of mine with 660s have enjoyed the hell out of it at 720p at around 60 fps. For whatever it's worth, I've even gotten it running in ugly but fun fashion on a Radeon 7750. If memory serves, the 950's just a nudge faster than the Radeon R7 370 in my home theater PC for Doom, and that manages 1600x900 on medium without a hitch, and is still enjoyably spry with high detail settings enabled. I do wonder what difference Vulkan will make when the time comes.

What's the real-world minimum resolution?

Topinio wrote:

kvndoom wrote:

I used to build/upgrade so frequently that I never had issues before. I just haven't kept up with the graphics war like I once did. I'm still in the refund window so I'm returning it. Do you think a 4GB GTX960 would be adequate for 2560x1440 or should I plunk down for a 970? I almost never buy new games, but I wanted DOOM for my birthday. It'll probably be the most taxing thing I play for the next 2 or 3 years, so I'm honestly basing my decision around that one game.

GTX 970 is not necessarily going to be great at 2560x1440 in Doom, I'd be looking at GTX 980 Ti or GTX 1070 level cards.

Way above my budget. Even the ~250 for a GTX970 is pushing it. I can dial down the resolution a lot easier than I can drop 400+ bucks on a video card.

Topinio wrote:

Concupiscence wrote:

The minimum real-world spec for Doom at around 60 fps is south of the 670; two friends of mine with 660s have enjoyed the hell out of it at 720p at around 60 fps. For whatever it's worth, I've even gotten it running in ugly but fun fashion on a Radeon 7750. If memory serves, the 950's just a nudge faster than the Radeon R7 370 in my home theater PC for Doom, and that manages 1600x900 on medium without a hitch, and is still enjoyably spry with high detail settings enabled. I do wonder what difference Vulkan will make when the time comes.

What's the real-world minimum resolution?

For what? Playing Doom in an enjoyable way? I'd say 720p, or 1024x768 for someone still gaming on a 4:3 monitor. You can play it at lower resolutions (or simulate them with the resolution percentage slider in the Advanced options), but it gets fuzzy and loses a lot of enjoyable sharpness. So realistically, on the Radeon side of the fence, probably a Radeon 7850, and Nvidia, a GTX 650 Ti. Various crazy people have uploaded YouTube videos of the game running on 1 gig GTX 560s and a Radeon 5830(!), but on average I don't think those will give reliably good performance. When I tried it on a GTS 450 the game was playable enough until I got to the third level, at which point the framerate tanked below 20 fps and I gave up.

kvndoom wrote:

Way above my budget. Even the ~250 for a GTX970 is pushing it. I can dial down the resolution a lot easier than I can drop 400+ bucks on a video card.

Sounds like maybe both? Shame about the issues with the RX 480, otherwise that with 4 GB at $200 could be ideal and might even get you nice settings at native 2560x1440.

Concupiscence wrote:

I'd say 720p, or 1024x768 for someone still gaming on a 4:3 monitor.

Good to know, maybe that GTX 950 would be okay at 1/4 res of the screen then.

Topinio wrote:

kvndoom wrote:

Way above my budget. Even the ~250 for a GTX970 is pushing it. I can dial down the resolution a lot easier than I can drop 400+ bucks on a video card.

Sounds like maybe both? Shame about the issues with the RX 480, otherwise that with 4 GB at $200 could be ideal and might even get you nice settings at native 2560x1440.

Concupiscence wrote:

I'd say 720p, or 1024x768 for someone still gaming on a 4:3 monitor.

Good to know, maybe that GTX 950 would be okay at 1/4 res of the screen then.

Nah, I'd expect the 950 to scream at 720p with a mix of medium and high detail settings, i.e. keep things at Medium but enable depth of field and self-shadowing.

People don't turn off depth of field instinctively? That's up there with motion blur with settings that I'd never keep enabled personally, regardless of performance impact or lack thereof.

slowriot wrote:

People don't turn off depth of field instinctively? That's up there with motion blur with settings that I'd never keep enabled personally, regardless of performance impact or lack thereof.

Having lived through the effect's terrible overuse in Unreal Engine 3 titles, I'm as surprised as anyone to admit that I like it in Doom. When it's not turned on there I miss it, and fumble into the menu to turn it back on. The motion blur's also very nice-looking, but only when it's set to Low in the main graphics menu. Nudging it any higher applies the effect to an obnoxious degree, and the game turns into a smeary mess if you so much as turn your head. I can live without the motion blur, but there are some moments where the depth of field's just pretty and visually distinctive.

To circle back around to the original subject of this thread: the 8 gig model's memory is clocked a bit faster, but the resulting performance delta amounts to 5-8%. However, that only applies if you're staying within 4 gigs of video memory; as VR and the new revision of XBox and Playstation 4 draw near, GPU memory will only become more important. I predict that the GTX 970 and 4 gig RX 480s will be pretty pinched within the next two years.

PCPer just claimed in their podcast (for the second time, they mentioned it in their review video of the RX 480 also) that the 4GB and 8GB are identical save for the VBIOS. They claim even the amount of memory is the same, that the only difference is memory speed and allocation of the additional 4GB. Theoretically a VBIOS flash could recover that extra 4GB, in fact they say in their review that they were given just one card with two VBIOSes to switch between for testing.

https://youtu.be/-rHG9hfTCGw?t=13m10s

I'm skeptical and a bit surprised but they did interview Raja Koduri just yesterday, there is no reason to get this wrong twice.

Topinio wrote:

TechPowerUp's performance summary chart from its RX 480 review might also help you quickly get back in the loop.

Thanks for that link! It really put things into perspective. I went ahead and ordered a GTX 970 today. Since the return window on my 950 is less than a week out, I can't wait for Nvidia to drop prices in response to the RX480.

puppetworx wrote:

PCPer just claimed in their podcast (for the second time, they mentioned it in their review video of the RX 480 also) that the 4GB and 8GB are identical save for the VBIOS. They claim even the amount of memory is the same, that the only difference is memory speed and allocation of the additional 4GB. Theoretically a VBIOS flash could recover that extra 4GB, in fact they say in their review that they were given just one card with two VBIOSes to switch between for testing.

https://youtu.be/-rHG9hfTCGw?t=13m10s

I'm skeptical and a bit surprised but they did interview Raja Koduri just yesterday, there is no reason to get this wrong twice.

On the one hand, that would explain the very low price difference between 4GB and 8GB cards.

On the other hand, it would be a PR disaster if proven true and the 8GB buyers paid $40 extra for thin air.

kvndoom wrote:

Thanks for that link! It really put things into perspective. I went ahead and ordered a GTX 970 today. Since the return window on my 950 is less than a week out, I can't wait for Nvidia to drop prices in response to the RX480.

yw, I really like that part of the TechPowerUp card reviews. Hope you enjoy Doom even more with your GTX 970.