Question Speculation: RDNA3 + CDNA2 Architectures Thread

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Timorous

Golden Member
Oct 27, 2008
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Why would they sell the cutdown N33 for the same price as N23 or <$300 when they can sell It for more?

Why would they make a 6GB part instead of 8GB?
With N23 we already saw the amount of faulty chips were negligible, If that wasn't true then they would have released such version for OEMs at least, but they didn't.
You will reduce cost by using only 3 chips instead of 4, but you also need chips with higher speed to compensate for the missing bandwidth, and they cost more.
You can have the same bandwidth by using 6GB Vram at 24gbps or 8GB Vram at 18gbps. So is there a noticeable difference in BOM between them? Buyers would certainly prefer more Vram.
I have told you.

1) you sell it for around $300 because lots of 2nd hand mining cards are going to be on the market and the financial situation is very different so I am not sure an entry level 7500XT could sell for much more than $300.

2) You make it 6GB because that reduces the memory cost by 25% and you reduce other parts of the BOM as well like cooling, power delivery etc. It also serves as a point of differentiation so that you don't harm 7600XT sales.
 

TESKATLIPOKA

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May 1, 2020
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I have told you.

1) you sell it for around $300 because lots of 2nd hand mining cards are going to be on the market and the financial situation is very different so I am not sure an entry level 7500XT could sell for much more than $300.

2) You make it 6GB because that reduces the memory cost by 25% and you reduce other parts of the BOM as well like cooling, power delivery etc. It also serves as a point of differentiation so that you don't harm 7600XT sales.
1) Is ~>=6700XT level of performance entry level? From when?

2)
Let's say full N33 needs 4x 24gbps memory chips. For the cutdown version you use only 3x 24gbps memory chips then you will save 25% of memory cost, but you can instead use 4x 18gbps memory chips for the same bandwidth. 18gbps chip is cheaper than the 24gbps one. So you won't save 25% of the memory cost.
By using 6GB Vram why would you save anything on cooling or power delivery? I would say you will save a tiny amount on assembly or PCB.

Using 18gbps memory instead of 24gbps is more than enough to differentiate a cut and uncut N33 + different number of enabled WGPs 14 vs 16.

The only positive by using 6GB Vram is maybe a bit lower BOM, nothing more. If there will be a 6GB version, then only later and because they have too many faulty chips.
 

Timorous

Golden Member
Oct 27, 2008
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1) Is ~>=6700XT level of performance entry level? From when?

2)
Let's say full N33 needs 4x 24gbps memory chips. For the cutdown version you use only 3x 24gbps memory chips then you will save 25% of memory cost, but you can instead use 4x 18gbps memory chips for the same bandwidth. 18gbps chip is cheaper than the 24gbps one. So you won't save 25% of the memory cost.
By using 6GB Vram why would you save anything on cooling or power delivery? I would say you will save a tiny amount on assembly or PCB.

Using 18gbps memory instead of 24gbps is more than enough to differentiate a cut and uncut N33 + different number of enabled WGPs 14 vs 16.

The only positive by using 6GB Vram is maybe a bit lower BOM, nothing more. If there will be a 6GB version, then only later and because they have too many faulty chips.
1) 6700XT is below entry level when it comes to RT and that will properly start to take off in the next few years. Also 8GB is not enough at 1440p anymore so no matter how it performs the vram is going to be a bottleneck.

2) or just use 20gbps chips on both because that is good enough for 1080p. When paired with 32mb cache.
 
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maddie

Diamond Member
Jul 18, 2010
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1) Is ~>=6700XT level of performance entry level? From when?

2)
Let's say full N33 needs 4x 24gbps memory chips. For the cutdown version you use only 3x 24gbps memory chips then you will save 25% of memory cost, but you can instead use 4x 18gbps memory chips for the same bandwidth. 18gbps chip is cheaper than the 24gbps one. So you won't save 25% of the memory cost.
By using 6GB Vram why would you save anything on cooling or power delivery? I would say you will save a tiny amount on assembly or PCB.

Using 18gbps memory instead of 24gbps is more than enough to differentiate a cut and uncut N33 + different number of enabled WGPs 14 vs 16.

The only positive by using 6GB Vram is maybe a bit lower BOM, nothing more. If there will be a 6GB version, then only later and because they have too many faulty chips.
Another issue with these die harvesting cut memory models is the difference between AMD and NVIDIA sales, 4:1 at present. Launching a new model (not free) for widespread use based on a defective memory controller, has AMD at a big disadvantage due to total numbers fabbed. The chance of a defective shader is much greater than a memory controller simply due to die area.

That's why we tend to see them as either OEM or close to the end of a generation when the numbers are at maximum.
 

TESKATLIPOKA

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May 1, 2020
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1) 6700XT is below entry level when it comes to RT and that will properly start to take off in the next few years. Also 8GB is not enough at 1440p anymore so no matter how it performs the vram is going to be a bottleneck.

2) or just use 20gbps chips on both because that is good enough for 1080p. When paired with 32mb cache.
1) I meant raster performance. I didn't even bother with RT because RDNA2 is so weak in It.
You say 8GB is not enough for 1440p then I have to ask If 6GB Vram is still enough for 1080p and for how long?

2) Didn't someone try to underclock the memory on N23 by let's say 25% for example to see how much It affects the performance at different resolutions? Then we will see how much BW N33 will need.
 

Timorous

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Oct 27, 2008
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1) I meant raster performance. I didn't even bother with RT because RDNA2 is so weak in It.
You say 8GB is not enough for 1440p then I have to ask If 6GB Vram is still enough for 1080p and for how long?
For a 7500XT 6GB will be fine. Far better than the 4GB 6500XT which is no faster than a 4GB 5500XT. If paired with 20gbps memory bandwidth will be 240GB/s which is a bit less than the 6600XT but RDNA3 does improve on compression reducing the bandwidth needs anyway so that should be absolutely fine for entry level 1080p / esports gaming.

A true 6500XT should have been in the region of 5600XT performance and 50-60% faster than a 5600XT is around 6700XT performance so a cut N33 that performs around 6700XT / 3070 tier is bang on for what a 7500XT tier part should perform like. 6500XT was a massive outlier and only existed because AMD were pipecleaning N6.

2) Didn't someone try to underclock the memory on N23 by let's say 25% for example to see how much It affects the performance at different resolutions? Then we will see how much BW N33 will need.
Don't know about underclocking but the 2% higher core and 9% higher memory clocks of a 6650XT translate to about 6% more performance at 1080p which indicates a slight memory bottleneck there. Again though RDNA3 has end to end compression so memory bandwidth requirements should go down slightly.
 
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TESKATLIPOKA

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For a 7500XT 6GB will be fine. Far better than the 4GB 6500XT which is no faster than a 4GB 5500XT. If paired with 20gbps memory bandwidth will be 240GB/s which is a bit less than the 6600XT but RDNA3 does improve on compression reducing the bandwidth needs anyway so that should be absolutely fine for entry level 1080p / esports gaming.

A true 6500XT should have been in the region of 5600XT performance and 50-60% faster than a 5600XT is around 6700XT performance so a cut N33 that performs around 6700XT / 3070 tier is bang on for what a 7500XT tier part should perform like. 6500XT was a massive outlier and only existed because AMD were pipecleaning N6.
Just because the cutdown N33 will be likely called as 7500XT doesn't mean It's of the same class as N24 or N14.
N33 is still N23's successor and that one had only 8GB Vram.
6500XT had only 4GB Vram, because you couldn't put more thanks to 64bit bus, the older 5500XT had 4GB or 8GB.
Now a far stronger and bigger GPU will have only 6GB Vram? In my opinion that's not very likely or not from the beginning.
If AMD releases a 6GB 96-bit model then only later, when It will have enough defective chips.
 
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Timorous

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Oct 27, 2008
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Just because the cutdown N33 will be likely called as 7500XT doesn't mean It's of the same class as N24 or N14.
N33 is still N23's successor and that one had only 8GB Vram.
6500XT had only 4GB Vram, because you couldn't put more thanks to 64bit bus, the older 5500XT had 4GB or 8GB.
Now a far stronger and bigger GPU will have only 6GB Vram? In my opinion that's not very likely or not from the beginning.
If AMD releases a 6GB 96-bit model then only later, when It will have enough defective chips.
It won't be from the beginning. I expect some shader only cut N33 to be used in laptops as well as full N33 in laptops.

I am simply saying that a viable 7500XT part does not need 8GB of vram to be perfectly capable in the target market. AMD are more likely to make a 7600 the shader only cut part with 8GB of maybe slower ram like they did with the 6600.

I just don't think AMD are going to make an N34 for the x500 series so will end up using N33 there too and to differentiate x500 from x600 giving x500 6GB just makes sense.

This will all be next year anyway so lets just wait and see what AMD actually do.
 

Glo.

Diamond Member
Apr 25, 2015
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If AMD releases a 6GB 96-bit model then only later, when It will have enough defective chips.
Yep. Initially, ONLY we get 7600 XT, with full die.

Every, even slightly, defective die will go to mobile, first, and potentially to OEM SFF/NUC computers(Minisforum, anyone?).

Desktop DIY is dying anyway.

And yes, if 7500 XT is released with 3072 ALUs, it will have 6 GB VRAM.
 

GodisanAtheist

Diamond Member
Nov 16, 2006
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Twould be interesting if AMD is going to have their discreet cards go down to the 7600 level, while their 7500/400/300 names are reserved for their next APU IGPU. Looking but cannot find a name for the Zen 4 IGPU. Rx7100i would be way too logical I suppose.
 

Glo.

Diamond Member
Apr 25, 2015
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Twould be interesting if AMD is going to have their discreet cards go down to the 7600 level, while their 7500/400/300 names are reserved for their next APU IGPU.
They are not. iGPU names will be similar in pattern to current APUs.

Radeon 780M, Radeon 880M.

Highest end may get the RX branding, also.
 
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KompuKare

Senior member
Jul 28, 2009
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I think the 4pm bit is new :)
That's a bit late for most of the world, isn't it?
Around midnight European time.
Shouldn't these things be early in the morning, to have it at a good time in most timezones?

Jumped on conclusion: they have nothing good to show and are trying to hide it from most of the world!
 

biostud

Lifer
Feb 27, 2003
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N32 is later I reckon. If they stuck to the same timing as RDNA 2, that would be Marchish for N32. I could see earlier.
I’m hoping for an early 23 launch along with zen4 3D. With the speed they are dumping rdna2 prices in the top end, they know sales will tank once they launch next gen.
 
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TESKATLIPOKA

Golden Member
May 1, 2020
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That's a lie.

You can connect two modules per 32bit bus. 64bit GPU can have 8GB Vram with 2GB modules (4x2GB)
Why I said It's impossible was because N24 is a total lowend and neither for AMD or Its partners It was worth It to use 2x more memory chips in clamshell mode, but physically It is possible, true.
 

maddie

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Jul 18, 2010
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I’m hoping for an early 23 launch along with zen4 3D. With the speed they are dumping rdna2 prices in the top end, they know sales will tank once they launch next gen.
I agree, the apparent rush to sell present gen products strongly indicate their future value or lack of. We're in a new world here and all stuck on old recent models are lost.
 
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