8th card added and PC won't boot.

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Bigbacon

Fully [H]
Joined
Jul 12, 2007
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trying to figure this out. my miner rig is the following
AMD 3200g
B450M
4gb ram
Sata hard drive
1000watt and 850 watt PSUs

I have 7 cards right now on risers connected to the those PCIe cards that have 4 USB ports on them so 8 total ports, 7 in use. Miner works fine with 7 cards in this config.

If I plug in an 8th card and power the card, PC won't post. unplug the power from the card, it posts. If riser for 8th card is still plugged into USB and power, it posts.

8th card works fine in another machine so it isn't the card. I've tried different risers to make sure it isn't a riser issue. Risers all work fine from test machine.

It isn't a power issue as I've tried running the 8th card from its own power supply to be sure.

Far as I can tell everything I have works as it should until that 8th card is powered.

Thought maybe it was a PCIe lane issue. Disabled anything that could possible use up lanes like the APU, ethernet, nvme/m.2 slot. no go. Tried the 8th card alone in the 3rd PCIe 1x slot so it wasn't attached to the 4 way card. didn't work.

plugged the monitor into every card just to make sure it didn't decide to change which card video was going to, it didn't.

What am I missing? am I hitting PCIe lane maximum maybe?
 
Those cards that convert a single PCIe x1 slot to 4 x1 slots do not use 4 lanes. They are only using 1 PCIe lane since they are plugged into an x1 slot. They use a PLX switch to make 1 lane work with 4 devices. With that said I'm not sure why the 8th card would make it not POST though so hopefully somebody else will have ideas on that, but you shouldn't be running into an out of lanes issue.
 
Tried a different USB cable? Maybe the signal degrades too much with that many extensions and risers.
 
Nobu said:
Tried a different USB cable? Maybe the signal degrades too much with that many extensions and risers.
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the cables are all pretty short, less than 3 feet i think.

I can swap any card I want in or out but as soon at there are 8 total being powered, its a no post.
 
Bigbacon said:
wtf does this even mean?
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It's a bios setting, but usually it comes into play before you get to that many cards. A lot of boards will POST and give you an "out of resources" message, etc. if it's not enabled. I would definitely try booting with only 7 cards though and go into the bios and check that. It should say "above 4g decoding" and needs to be enabled. Should be in the chipset section of the bios. Some older motherboards need a bios update to show the option.

I would try to bump to 8GB ram in that machine too if you have an extra stick you can throw in to test.
 
I'll look, I was in the bios before disabling anytihng that I didn't need to be enabled. don't recall any setting like that. its a pretty low end board i think.
 
I think it allows devices to use memory past 4GB (Gb?) in RAM for initialization. It's usually not an issue, but some devices use a lot, and if you have multiple devices which use a lot you can run past that limit.
 
ok 4G setting didn't change anything.

Also plugged in a PC speaker and it doesn't even give a beep code when the 8th card is plugged in. Like the machine is just dead.
 
What happens when you move one of the 7 existing cards to the riser/slot you intent to use for the 8th card?
 
uOpt said:
What happens when you move one of the 7 existing cards to the riser/slot you intent to use for the 8th card?
Click to expand...

The riser works fine. I can use that riser by itself like it is now on another PC, i can unplug one of the other risers and plug this one in and it works.
 
I think I just need a different motherboard. I can see people getting 12 cards on one board but they are usually full ATX boards and they don't use more than one of these 4 USB cards things. so they get 4 from the primary 16x slot, and then use all the other slots with just a single card and even put adapters in the m.2 slots.

my board has 1 16x slot, the other two are 1x only. I think the fact that I can get 7 out of it is probably more than I could ask for from it. just sucks having another computer spun up for one card....and its an old AMD Athlon X2 3800+ machine.
 
Bigbacon said:
I think I just need a different motherboard. I can see people getting 12 cards on one board but they are usually full ATX boards and they don't use more than one of these 4 USB cards things. so they get 4 from the primary 16x slot, and then use all the other slots with just a single card and even put adapters in the m.2 slots.

my board has 1 16x slot, the other two are 1x only. I think the fact that I can get 7 out of it is probably more than I could ask for from it. just sucks having another computer spun up for one card....and its an old AMD Athlon X2 3800+ machine.
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What's the problem? Just get 6 more GPUs to go with it so it's not lonely.
 
Andrew_Carr said:
What's the problem? Just get 6 more GPUs to go with it so it's not lonely.
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because there is no way the 2006 era board is going to enjoy that, I'm amazed a 3000 series card is even happy running by itself. I would still need to get another motherboard/cpu/ram combo.
 
Bigbacon said:
I boufht one. See how it goes. Figure if it doesnt work and aliexoress is annoying to refund ill just charge back
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They are surprisingly good at giving your money back at least in my experience. A seller was being stubborn to give me a refund/replacement for some server PSUs I bought that were used and didn't even power on, opened a dispute with aliexpress, recorded a video of the items not working and they promptly refunded me.
 
All I know is that the PC doesn’t boot to BIOSis if the motherboard or the CPU's power connector is not plugged correctly. That’s surely the first thing to check.
 
Agraffe said:
All I know is that the PC doesn’t boot to BIOSis if the motherboard or the CPU's power connector is not plugged correctly. That’s surely the first thing to check.
Click to expand...

lol wut??? you didn't read anything did you.
 
I just got a bunch of these 6U GPU cases for $150 to $170 apiece on ebay but now they've shot up in price. Hopefully they come back down, but 4U cases are available now for $200 which is better than in the past at least.

The all black ones fit pretty snugly into my racks while the silver ones are made of better steel / quality (both are better than the grey matter chinesium). Drawback with the silver steel ones though is that they're 10.5 inches tall so half an inch shorter so giant GPUs with power connectors on top barely fit, and you can't really get a wraith CPU cooler in them. The black ones will fit basically 6 of any massive GPU and still let you put in a 3900x build underneath. They both have a drawback of having the PSU exhaust in the front, but with the black ones you can at least reverse them and mount them backwards whereas the silver ones have a giant gaping hole in the back (great for airflow I guess). Overall I'm pretty happy with both types. It's way easier to install current gen GPUs into these than into smaller cases and cable management is simple: shove everything under the riser bar and in-between the two PSUs. Going to install them all into racks next weekend so I might do a write-up on the whole process once complete. Trying to find ears for them currently.
 

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