Friday, May 15th 2020

GIGABYTE B550 AORUS Master Waltzes Around Chipset Limitations to Provide Three Gen 4 M.2 Slots

GIGABYTE B550 AORUS Master is the company's most premium socket AM4 motherboard based on the upcoming AMD B550 chipset. We described this board in some detail in our older article covering an assortment of top B550 motherboards from manufacturers, but missed a key bit. At the time we assumed that the PCI-Express lane switches located below the board's main PCI-Express slot merely split its x16 connection from the AM4 SoC down to two x8 connections to share between two slots, given that AMD allows multi-GPU (including SLI) with the B550. Apparently, the lane switches are there for a different, more fascinating reason.

A BenchLife.info report points to the possibility of all three M.2 slots on this motherboard having PCI-Express gen 4.0 wiring - something that shouldn't normally be possible, since all downstream PCIe lanes put out by the B550 are gen 3.0. The way we see it, the topmost M.2 slot has a direct PCI-Express 4.0 x4 connection from the AM4 socket (as it normally should). The second- and third slots, however, pull their wiring from a series of lane switches that split the main x16 PEG slot to gen 4.0 x8/x4/x4. It's possible that one of the two x16 (electrical x4) slots has a further lane sharing arrangement with one of the two M.2 slots.
When paired with a "Matisse" or "Vermeer" processor, the main PEG slot will run at full x16 bandwidth until one of the bottom two M.2 slots is populated, at which point the x8/x4/x4 configuration is engaged. When paired with a "Renoir" APU, however, it's likely that the bottom two M.2 slots are completely disabled, since the APU only spares 8 lanes toward PEG, which make up the first 8 (permanent) lanes on the PEG slot. The B550 chipset's 8-lane PCIe gen 3.0 budget is spent driving the board's various onboard controllers (except HD Audio, which is wired to the CPU), and one of the x16 (electrical x4) slots. GIGABYTE is expected to launch the B550 AORUS Master sometime mid-June, 2020.
Source: BenchLife.info
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39 Comments on GIGABYTE B550 AORUS Master Waltzes Around Chipset Limitations to Provide Three Gen 4 M.2 Slots

#1
Houd.ini
How much is this mobo? I fear we’re creeping into x570 territory, and then what’s the point?
Posted on Reply
#2
Chaitanya
Houd.ini
How much is this mobo? I fear we’re creeping into x570 territory, and then what’s the point?
B550 already offers better connectivity than X470 and given top end X470 motherboards were around 200$, expect these top end B550 boards to sit below that price. Also VRM seems to be borrowed from X570 boards which for entry level boards is a very nice addition.
Posted on Reply
#3
TheLostSwede
Oh look, I mentioned this on the news post over a week ago...
The final PCIe 3.0 x1 lane is obviously going for the Wi-Fi card, not USB 3.x.
www.techpowerup.com/forums/posts/4259445
Houd.ini
How much is this mobo? I fear we’re creeping into x570 territory, and then what’s the point?
The point is, if you can live with eight PCIe lanes for your graphics card, you get more bandwidth for other peripherals.
The additional cost for this type of layout is most like not more than $5-10 in parts, depending on the current cost of PCIe 4.0 switches.
Posted on Reply
#4
Houd.ini
TheLostSwede
The point is, if you can live with eight PCIe lanes for your graphics card, you get more bandwidth for other peripherals.
The additional cost for this type of layout is most like not more than $5-10 in parts, depending on the current cost of PCIe 4.0 switches.
I could probably live with that, but again, at what cost? $5-10 in parts relative to what? If it's more than 200 USD I'd rather get a proper x570 board.
Posted on Reply
#5
Tsukiyomi91
if it's well within the $200 range without butchering the X570s, this particular board would be a good consideration.
Posted on Reply
#6
TheLostSwede
Houd.ini
I could probably live with that, but again, at what cost? $5-10 in parts relative to what? If it's more than 200 USD I'd rather get a proper x570 board.
That I don't know, but as it's an Aorus Master board, it's most likely their top of the range B550 board, so it might be north of $200.
Posted on Reply
#7
dj-electric
People for some reason think there wont be cross pricing between high end B550 boards and budget X570 boards, I dont get why.
Not every X570 board is going to do everything better than every B550 board, get that out of the system.
B550 is 99$ and upwards, and if AIBs want to make 250$ ones, they will, and include components to their hearts and technical limitations content.
Posted on Reply
#8
Houd.ini
dj-electric
People for some reason think there wont be cross pricing between high end B550 boards and budget X570 boards, I dont get why.
Not every X570 board is going to do everything better than every B550 board, get that out of the system.
B550 is 99$ and upwards, and if AIBs want to make 250$ ones, they will, and include components to their hearts and technical limitations content.
I am glad I never said that, because that would be foolish. I just don't get the appeal for (potentially) expensive midrange boards when you can get good x570 boards for around 200 USD. It depends on the features and pricing of course, but we already know B550 is nerfed compared to x570 in terms of PCI-E lanes at least.
Posted on Reply
#10
dj-electric
Houd.ini
I am glad I never said that, because that would be foolish. I just don't get the appeal for (potentially) expensive midrange boards when you can get good x570 boards for around 200 USD. It depends on the features and pricing of course, but we already know B550 is nerfed compared to x570 in terms of PCI-E lanes at least.
Its just that PCIE lane amount and version isnt everything. What B550 offers covers most of what enthusiasts use anyway, but AIBs still have the freedom for beefy VRM systems, TB3 / 10G ETH / what have you.
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#11
Octopuss
Why is there mixture of PCIe 3 and 4 anyway?
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#12
dj-electric
Octopuss
Why is there mixture of PCIe 3 and 4 anyway?
The chipset itself is just a PCIE3 type controller (just like X470), so that's what provides those.
Posted on Reply
#13
Octopuss
And it doesn't need to have higher speed into the CPU?
Damn I'm behind.
Posted on Reply
#14
dj-electric
Octopuss
And it doesn't need to have higher speed into the CPU?
Damn I'm behind.
Communication channel to the CPU is still 3.0 X4, so that's where its own IO devices will communicate through to the CPU, sure.
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#15
jmcslob
dj-electric
Its just that PCIE lane amount and version isnt everything. What B550 offers covers most of what enthusiasts use anyway, but AIBs still have the freedom for beefy VRM systems, TB3 / 10G ETH / what have you.
I agree and disagree with what you're saying.
2 NVMe drives and 1 GFX and you already have a slowdown on potential performance on a 550.
There are x570's that cost less than $150 that already have more useable potential than any 550...
But none of that is going to affect the average user whatsoever and will get to enjoy every benefit of PCI-E 4.0
The thing about beefy VRMs is unless you're buying the upper end "good enough" is good enough.
AMD has such a good binning system that OC'ing for most is 100 maybe 200mhz.
If you want a faster AMD...buy it and spend less on the mobo.

If 550's are more than $99 they're not worth it for any reason

EDIT:
The splitting of PCI-E lanes matter..1x 16 and 1x 4 with a chipset 3.0x 4 speed limitation
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#16
gamefoo21
That's kinda like how it's done on some X570 boards.

They do: x16,0,0 - x8,x8,0 - x8,x4,x4

The trade off is that you get to use the m.2 x4 lanes without giving up the 1x slots *cough* MSI *cough* or your sata ports.

Honestly PCIe 3.0 is fast enough for most NVME drives. The only 4.0 drives that keep sustained speeds high enough cost Linus money and are add in card format.

Though if you add in a third slot device no SLI for you!
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#17
Dammeron
Is there no USB C front header, or am I just blind?
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#18
Battler624
that board looks so good it makes me regret my aorus elite x570
Posted on Reply
#19
TheLostSwede
Houd.ini
I am glad I never said that, because that would be foolish. I just don't get the appeal for (potentially) expensive midrange boards when you can get good x570 boards for around 200 USD. It depends on the features and pricing of course, but we already know B550 is nerfed compared to x570 in terms of PCI-E lanes at least.
Did you read the fine print from say MSI? Their cheap X570 boards also use PCIe 3.0 on some slots, as that way they didn't need to add the PCIe redrivers, so they saved a few bucks.
dj-electric
The chipset itself is just a PCIE3 type controller (just like X470), so that's what provides those.
X470 is only PCIe 2.0, not 3.0.

jmcslob
I agree and disagree with what you're saying.
2 NVMe drives and 1 GFX and you already have a slowdown on potential performance on a 550.
Incorrect, as the graphics cards and the first M.2 slot is connected directly to the CPU.
gamefoo21
That's kinda like how it's done on some X570 boards.

They do: x16,0,0 - x8,x8,0 - x8,x4,x4

The trade off is that you get to use the m.2 x4 lanes without giving up the 1x slots *cough* MSI *cough* or your sata ports.

Honestly PCIe 3.0 is fast enough for most NVME drives. The only 4.0 drives that keep sustained speeds high enough cost Linus money and are add in card format.

Though if you add in a third slot device no SLI for you!
Show me one board that is like that.
x8,x8, sure, but nothing more, as there's no reason for it. The last x4 slot should always be connected to the chipset and I haven't seen any board that doesn't do this, that has a third x16 slot. In fact, I'm using the x4 slot on my board with a 10Gbps Ethernet card and it's not shared with anything else in my system.
As per below, there's no reason to do something like that.

Posted on Reply
#20
gamefoo21
TheLostSwede
Did you read the fine print from say MSI? Their cheap X570 boards also use PCIe 3.0 on some slots, as that way they didn't need to add the PCIe redrivers, so they saved a few bucks.


X470 is only PCIe 2.0, not 3.0.




Incorrect, as the graphics cards and the first M.2 slot is connected directly to the CPU.


Show me one board that is like that.
x8,x8, sure, but nothing more, as there's no reason for it. The last x4 slot should always be connected to the chipset and I haven't seen any board that doesn't do this, that has a third x16 slot. In fact, I'm using the x4 slot on my board with a 10Gbps Ethernet card and it's not shared with anything else in my system.
As per below, there's no reason to do something like that.


X570 TaiChi does the three slot tango if the spec sheet and bios are to be believed.
Posted on Reply
#21
TheLostSwede
gamefoo21
X570 TaiChi does the three slot tango if the spec sheet and bios are to be believed.
Fair enough. No idea why they did that, as it's not even cost effective, as the PCIe 4.0 switches can't possibly be cheaper than the re-drivers.
I guess they picked 8 SATA ports over having a sensible PCIe layout.
Posted on Reply
#22
Imsochobo
TheLostSwede
Fair enough. No idea why they did that, as it's not even cost effective, as the PCIe 4.0 switches can't possibly be cheaper than the re-drivers.
I guess they picked 8 SATA ports over having a sensible PCIe layout.
Page 29
download.asrock.com/Manual/X570%20Taichi.pdf#page=36&zoom=100,0,0

They don't do anything funny it seems as they disable last pci-e 4.0 from chipset with 3rd m2 installed.
Bios option is available to any asrock x570 board for (4x4x4x4) that is Bifurcation of your 16x slot\lanes for either 8x\8x or 4x4x4x4x
Posted on Reply
#23
TheLostSwede
Imsochobo
Page 29
download.asrock.com/Manual/X570%20Taichi.pdf#page=36&zoom=100,0,0

They don't do anything funny it seems as they disable last pci-e 4.0 from chipset with 3rd m2 installed.
Bios option is available to any asrock x570 board for (4x4x4x4) that is Bifurcation of your 16x slot\lanes for either 8x\8x or 4x4x4x4x
That really is a terrible manual. But yeah, it seems the manual contradicts the spec page... Good job Asrock...

This is going to be an insane mess for people to understand when they get a B550 board and wants to put things in all the slots, as people just expects it to work if there's a spare slot.
Posted on Reply
#24
jmcslob
TheLostSwede
Incorrect, as the graphics cards and the first M.2 slot is connected directly to the CPU.
That's what I'm trying say. Once you add a 2nd NVMe its got to be PCI-E 3.0 on the 550 as the chipset itself is only on a PCI-E 3.0
That's not exactly a problem at the moment. Probably won't be for most.
Posted on Reply
#25
TheLostSwede
jmcslob
That's what I'm trying say. Once you add a 2nd NVMe its got to be PCI-E 3.0 on the 550 as the chipset itself is only on a PCI-E 3.0
That's not exactly a problem at the moment. Probably won't be for most.
Hence the article, as Gigabyte found a weird workaround for that, of sorts.
Posted on Reply
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