Noises About Radeon HD 7900 Series with XDR2 Memory Grow

[cadaveca]

Type of memory is unrelated to PCI-E lanes.

IOMMU in 7-series GPU. That is all.

Pretty sure ECH was thinking about this when mentioning PCI-E. I am sure he was wondering is PCIe bandwidth was enough to take full advantage of the bandwidth offered by XDR2.

Not all users use VGAs for gaming..GPGPU has it's purposes too.

 

[EastCoasthandle]

And it doesn't, there's nothing limiting the card from using XDR on PCI-E 2.0 x16.



Really? I'm clearly ignorant eh? Way to go buddy. Yes, they ARE kinds of SDRAM. But they DIFFER between each. Full stop.

LOL, I'm talking about a 7970 with XDR2 vs 7970 using GDDR5 in current vs next gen PCIe. I should have made "it" more clear but that's what I was referring to.

 

[John Doe]

IOMMU in 7-series GPU. That is all.

Pretty sure ECH was thinking about this when mentioning PCI-E. I am sure he was wondering is PCIe bandwidth was enough to take full advantage of the bandwidth offered by XDR2.

Not all users use VGAs for gaming..GPGPU has it's purposes too.

LOL, I'm talking about a 7970 with XDR2 vs 7970 using GDDR5 in current vs next gen PCIe. I should have made "it" more clear but that's what I was referring to.

PCI-E has sufficient bandwidth to make use of memory. Do you have an idea on how much bandwidth PCI-E x16 2.0 can provide? How much of it is used by memory? A miniscule amount.

 

[largon]

You are currently running DDR3-SDRAM.

Right, instead of SDR-SDRAM (Single Data Rate Synchronous Dynamic Random Access Memory).
John Doe obviously referred to data rate with "SD" (SDR-SDRAM), not the basic type of the DRAM.

You're being a pedant for no reason.

 

[EastCoasthandle]

PCI-E has sufficient bandwidth to make use of memory. Do you have an idea on how much bandwidth PCI-E x16 2.0 can provide? How much of it is used by memory? A miniscule amount.

I see, LOL you must be having a bad day arguing with people here. Let me put it this way as I really find your reply silly. I want to see the benchmark results and find your reply pointless.

 

[John Doe]

I see, LOL you must be having a bad day arguing with people here. Let me put it this way as I really find your reply silly. I want to see the benchmark results and find your reply pointless.

Does DDR to GDDR3 make difference from AGP to PCI-E x16? It doesn't. Memory as a whole doesn't matter to a significant amount. It doesn't make enough difference to be noticeable from one type to another, let alone from one interface to the other. What matters is the GPU itself; it's core. Not the memory, which is why your arguement is pointless.

 

[cadaveca]

Memory controller interfaces with system ram, via DMA, over PCIe bus.

XDR2 has it's own specialized controller, which may affect how system memory is accessed. PCIe 3.0 offers less overhead, which may make transfers faster over PCIe 2.0, if done right.

Add in the IOMMU, for additional system ram accesses, and yes, the interface used might play a role.


I'm not sure why you think it's a moot point. Nothing wrong with answering a question, now is there?

 

[John Doe]

Memory controller interfaces with system ram, via DMA, over PCIe bus.

System RAM is sufficiently fast. Like I said, nothing is limiting XDR2. For a fact, nothing is limiting PCI-E 2.0 at all. That's why 3.0 still isn't set up yet.

XDR2 has it's own specialized controller, which may affect how system memory is accessed. PCIe 3.0 offers less overhead, which may make transfers faster over PCIe 2.0, if done right.

Add in the IOMMU, for additional system ram accesses, and yes, the interface used might play a role.

You're talking as if mem performance matters over what we currently have. Not to a significant amount, and 2.0 already has low overhead.

 

[EastCoasthandle]

Does DDR to GDDR3 make difference from AGP to PCI-E x16? It doesn't. Memory as a whole doesn't matter to a significant amount. It doesn't make enough difference to be noticeable from one type to another, let alone from one interface to the other. What matters is the GPU itself; it's core. Not the memory, which is why your arguement is pointless.

Your post is pointless. You can't reference older ddr or gddr3 to AMD's next gen video cards using current hardware. Which is why I said the tests should be done. Get mad all you want but your entire reasoning, referencing old hardware is the very reason why I made the suggestion. The only way to know what the results are is if it's tested once it's made available.

 

[cadaveca]

For a fact, nothing is limiting PCI-E 2.0 at all.

System ram efficiency affects GPU performance. Just fire up a CodeMasters title to see what I mean. I use F1 2010 in my board reviews specifically because it's so sensitive to system ram performance.

You're talking as if mem performance matters over what we currently have

The addition of an IOMMU into the GPU itself does make the memory subsystem a bit more important for GPGPU. Gaming...time will tell.

 

[John Doe]

Your post is pointless. You can't reference older ddr or gddr3 to AMD's next gen video cards using current hardware. Which is why I said the tests should be done. Get mad all you want but your entire reasoning, referencing old hardware is the very reason why I made the suggestion. The only way to know what the results are is if it's tested once it's made available.

What's done will be done. The card isn't out yet, so the closest comparison I can do would be with older hardware.

System ram efficiency affects GPU performance. Just fire up a CodeMasters title to see what I mean.

Bullshit.

http://www.anandtech.com/show/2792

 

[cadaveca]

Bullshit.

http://www.anandtech.com/show/2792

Reading comprehension in important. I said Bandwidth efficiency, not speed. There is very much a huge difference between the two.

Slower CPU, but faster memory, wins. Note that both are using identical ram speeds(1333 MHz 9-9-9-24). The APU platform is far more efficient at memory control than Thuban's.

I make a point of using benchmarks anyone can replicate.

 

[John Doe]

Reading comprehension in important. I said Bandwidth efficiency, not speed. There is very much a huge difference between the two.

Neither changes anything in this case since both PCI-E 2.0 and DDR3 already have a fast balance.

Slower CPU, but faster memory, wins. Note that both are using identical ram speeds(1333 MHz 9-9-9-24). The APU platform is far more efficient at memory control than Thuban's.

I make a point of using benchmarks anyone can replicate.

That doesn't have anything to do. It's comparing a different CPU memory controller to the other, not lane controller or faster memory to slower.

 

[cadaveca]

That doesn't have anything to do. It's comparing a different CPU memory controller to the other, not lane controller or faster memory to slower.

That's exactly my point. XDR2 has it's own controller, which will use the PCIe bus to communicate with system ram. Like how the APU controller makes better use of the bandwidth available, likewise, XDR2's controller may as well. This may place greater load on the PCIe bus.

This is doublied by the addition of an IOMMU, which is basically just yet another memory controller, but one specific to System Memory Access, rather than both accessing system memory, and onboard caches. Perhaps the use of the IOMMU is needed with the XDR2 contorller, or perhaps not...time will tell.


It's something to be aware of, and to look at, when and if this new technology is used. This also bolster's ECH's interest in if PCIe matters..he never said it would matter...he was curious how it will play out. Could amount ot nothing, of course, but it's far to early to tell.

 

[chron]

And it doesn't, there's nothing limiting the card from using XDR on PCI-E 2.0 x16.



Really? I'm clearly ignorant eh? Way to go buddy. Yes, they ARE kinds of SDRAM. But they DIFFER between each. Full stop.

He's just saying you were ignorant about one small fact, not in general.

 

[John Doe]

He's just saying you were ignorant about one small fact, not in general.

No, I wasn't. I referred to "SD" and "SDR" RAM. Not as DDR RAM. It's only uninformed if you don't know what you're reading.

 

[OneCool]

It's only a matter of time before RAMBUST sues AMD too. LOL

They did

 

[theubersmurf]

The prices Rambus charges puts their products out of the consumer range. This isn't happening, I'm confident. This is just scuttlebutt.

 

[mastrdrver]

There is no manufacturer of memory currently even making XDR2. So how are you suppose to validate a memory controller without any memory chips? How are you suppose to make cards without any memory to put on them so you can validate the card?

I wish there was a black hole on the internet where we could put this XDR2 rumor so it would never return.

 

[chron]

There is no manufacturer of memory currently even making XDR2. So how are you suppose to validate a memory controller without any memory chips? How are you suppose to make cards without any memory to put on them so you can validate the card?

I wish there was a black hole on the internet where we could put this XDR2 rumor so it would never return.

The industry is probably at a point where they can see where things are going with a certain kind of technology, even when it's at it's infant stage.

 

[Casecutter]

It's only a matter of time before RAMBUST sues AMD too. LOL

Yep they had litigation, but we weren’t actually made privy to what to an exact settlement. Could have RAMBUS and AMD worked out an agreement for use of technology? RAMBUS honestly at some point needs to find someone, they aren’t friendly with Nvidia so AMD is a likely partner.

The prices Rambus charges puts their products out of the consumer range. This isn't happening, I'm confident. This is just scuttlebutt.

Well that was back a long time ago, and then it really never made it to market so hard to say that position is valid today with the right partner. While it will be the premium offering on the highest end offer card. If it works... there will be takers

There is no manufacturer of memory currently even making XDR2. So how are you suppose to validate a memory controller without any memory chips? How are you suppose to make cards without any memory to put on them so you can validate the card?

So what’s Rod Dhat Solution Marketing Manager for RAMBUS using? How do you know who is or who’s not making chips? Then why did AMD seemingly start branding Radeon memory that might have been Hyundai (Hynix)? Your entire dither presents the dumbest argument. You're saying a company like AMD can’t find somewhere/someone to make R&D samples and production? ...wow is your thinking that pathetic!

 

[MarcusTaz]

Jeeze will you all stop your bitching...

IF this thing has XDR2 I want it !!!

 

[Relayer]

Because of the extra bandwidth not only would 256 mem bus be still usable on next generation high end, but 128 could be used on GPU's as powerful as the current 6970 making the GPU's smaller and cheaper. Since AMD sells GPU's (at least after the initial release of reference cards) not complete cards or the RAM chips, it would make the product they sell cheaper to produce. They've already paid the licensing, which I read runs out this year, I see no reason for AMD not to do it. Providing of course it's readily available and the engineering isn't so hard as to hold back production.

Add to that AMD seems to like to be ahead of the curve vs. nVidia with new tech.

 

[John Doe]

Add to that AMD seems to like to be ahead of the curve vs. nVidia with new tech.

Yeah, that's what you do when your GPU isn't as powerful. Fanboyism is stupid ain't it?

 

[de.das.dude]

System RAM is sufficiently fast. Like I said, nothing is limiting XDR2. For a fact, nothing is limiting PCI-E 2.0 at all. That's why 3.0 still isn't set up yet.



You're talking as if mem performance matters over what we currently have. Not to a significant amount, and 2.0 already has low overhead.

so you would prefer a 6990 with 4 gigs of cheap ass DDR3 rather than GDDR5.