Computing bandwidths of various cards under Ethereum

Abszol D

9/19/23, 10:46 PM

I'm writing my term paper on bandwidth restrictions between varying generations of PCI-E lanes using the 1x interface of the lane and exploring modern bandwidth restrictions when mining using the latest GPUs.

GPU risers themselves use the 1x lane and I've been looking at the PCI-E wiki to analyze these restrictions: https://en.wikipedia.org/wiki/PCI_Express

Now I know my Motherboard supports PCI-E 2.0 (12x) and PCI-E 3.0 (1x), which all my GPUs are plugged into the 2s.

I sat down and did the math to which became confused:

We can speculate under the notion we're mining 

Ethereum.
Ethereum Hash => 64 hexadecimal characters or 256 bits.
RTX 3090 - 125 MH/s (Megahashes a Second) close to average.
                  
How many bits?  
1 MegaByte (MB) = 1000000 Bytes.
Therefore we can substitute bytes with hash in this case as they're near synonymous.
125 MH/s = 125 * 1 H / (1000000 MH) = 125000000 H/s.                                                 
Now convert hash to bits.
125000000 H/s = 125000000 * 256/1 bits/hash = 32000000000 b/s (bits/second).
Finally convert bits/second to MegaBytes and GigaBytes.
Remember 1000000 Bytes = 1 MB and there's 8 bits in a byte.
Therefore          
1 MB (MegaByte) = 8000000 b.
32000000000 b/s = 1 MB / (8000000 b) = 4000 MB/s.
                   
MB: 4000 MB/s.  
GB: 4 GB/s.       
                  
Therefore the RTX 3090 (125 MH/s) requires a data bandwidth of 4 GB/s.

There's definitely preconceived notions shown here and any clear ups as to:

How is it pulling 4GB/s while PCI-E 2.0 only supports up to .500 GB/s on the 1x interface when using a riser.
Am I missing anything or over speculated the size of the hashes, etc.

Thanks! Any help is appreciated.

0 + 0

hash

Maarten Bodewes

9/20/23, 5:09 AM

For mining you don't export the intermediate hashes, you export the coins.

Maeher

9/20/23, 7:04 AM

What's the cryptography question here? It seems to me this question is purely about hardware restrictions and maybe confusion about how mining Ethereum works. As such it would be off-topic.

user253751

9/20/23, 9:10 AM

You are assuming that the CPU needs to receive all the hashes instead of just the ones that work

Abszol D

9/20/23, 2:26 PM

@Maeher you're definitely right that it's more leaning towards hardware than cryptography as I'm measuring the bandwidth supported by the interfaces and potential future issues. There's no exchange for hardware, only hardware recommendations.

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: Computing bandwidths of various cards under Ethereum

TH: การคำนวณแบนด์วิธของการ์ดต่าง ๆ ภายใต้ Ethereum

RO: Calcularea lățimii de bandă a diferitelor carduri sub Ethereum

RU: Вычисление пропускной способности различных карт под Ethereum

VI: Tính toán băng thông của các loại thẻ khác nhau trong Ethereum

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