Ah yes had forgotten that, and was going off memory for the rating. Maybe I'll go with 2x 6pins for 3 GPUs for safety, giving 384W of rating for 225W of draw.


Yeh, I think I'll go for 3.5 slot spacing giving a PCB size of roughly 425mm (any bigger and you will struggle with screws, tolerances, etc), which would fit neatly behind 3x140mm fans as you describe. Thanks for the helpful feedback!


As you say, 2 slot, meaning you then need 4 PCIe risers adding $32 more to sufficiently space them bringing the total to $57 dollars, whilst I won't get near that I will hopefully not laugh in the face of the PCIe standards that these risers do and be far more reliable... and these still don't allow you to run 12+ GPUs off the most bog standard motherboards.

Started putting together a schematic which will allow me to build a BOM and cost it up. Will try and add '+£' figures for any options to get peoples opinions on them.

Does anyone know the sort of PCIe bandwidth mining with a GPU actually uses, as in would a single x1 slot be sufficient for 6 GPUs or is that pushing it a bit? If so price could definitely be decreased and even lower end motherboards utilised.

It will only load the PCIe socket draw of 2 GPUs, not the whole GPU, will be on 1 PCIe 6 Pin connector so 150W @12V, I'm quite happy to incorporate 1 per GPU but people will just use splitters anyway which are far more dangerous than a PCB based solution. Each contact of PCIe connector is rated at 9A, equating to 27A total draw limit for the connector or a 324W @12V limit, the PCIe standard is very conservative in this matter.


4-6 slot spacing isn't really possible for a single PCB solution, it would be far too big. Exhaust fans and sufficient air extraction are the best way of preventing warm exhaust air from getting to any other GPUs. Intelligent purchasing of GPUs for the particular situation will always be a factor with noise to cooling capability the main factor, and I'd argue that GPUs with horizontally aligned heatsinks are sufficient as well as blower style to keep decent airflow at low noise levels, however testing would obviously be necessary. However, only the most extreme coolers tend to go over 2 slots these days.

It could possibly be increased to 3.5 slot but would no longer neatly fit behind 3 120mm fans.

I've been considering developing a 6 GPU riser/backplane using a PLX chip allowing the 6 GPUs to be hosted by a x4 PCIe 2.0 Slot, and giving each a x1 PCIe 2.0 Slot using an off the shelf x4 riser to link the motherboard and backplane. What are peoples thoughts on this? A worthwhile project? Would people be interested in such a product?
It would allow practically any motherboard to hit it's GPU hard limit but would cost more than 6 of the normal x1 risers due to the extra electronics involved (the IC alone is about £40...), however it wouldn't bypass 4G decoding support.

The idea is to give GPUs 3 slots each meaning the board size would be approximately 360mm wide to fit neatly behind 3 fans and/or in a rackmount chassis. It would use 1 6pin PCIe connector for every 2 GPUs.

Other additional features could include:
Support for 6 PWM high power fans requiring an additional 1 or 2 6 pin PCIe connectors with manual adjustment with a breakout board.
Hotswap/Overcurrent/Overvoltage protection/indication for the GPUs (1 IC does it all).
Debug lights.
Possibly others?

I am an digital electronic engineer by profession so I'm not jumping into this completely blind.

Any thoughts, feelings or feedback would be appreciated.

The chassis is very short (380mm deep) and we recommend that chassis runners are used to mount the server in the rack, a solution used by many small businesses to save costs on expensive rails.

Please bare in mind you are looking at GBP prices converted into USD, hardware in the UK is significantly more expensive than the USA with prices usually 1:1 USD to GBP, at least. The prices also include UK VAT, if a US customer was to get in contact this could be removed, bringing the prices down 20%, unfortunately this cannot be directly implemented in the website as this could be easily exploited. Obviously tax would still have to be paid by the customer on the units entering the US.

I find it interesting that you include risers in your quality components...
I'm also trying to produce a product that doesn't require an angle grinder to install the components.

I agree with you on the sticker, but that is Chinese branding for you. However, these are tried and tested power supplies.

In regards to airflow, the 3 190CFM Delta fans provide plenty and can be adjusted to suit with the supplied fan controller, the GPUs in the 8 card prototype are currently around 55-58C at 2/3 fan speed.

As a note, in terms of reliability the prototype units both worked immediately after installing all the graphics cards and SMOS and have worked for 3 months without any downtime so far apart from a power cut about 2 days ago.

Hello all,

Rackmount Mining is proud to present its first product, the X7R 4U Server, offered in both a barebones and turn-key solutions.
The X7R represents the only riserless rackmountable chassis on the market, allowing improved airflow and reliability over conventional riser systems.

We are currently taking pre-orders for batch 1 of units consisting of 50 servers. This has an estimated arrival to us at the end of April.
If batch 1 sells quicker it will arrive quicker! You will be kept fully updated through the pre-order, build and testing process.

All servers are fully tested for 48 hours and come with a 1 year warranty.

Visit our website to learn more:

Website: https://rackmountmining.co.uk/
Facebook: https://www.facebook.com/rackmountmining/
Email: info@rackmountmining.co.uk

FAQ:
Do you except escrow?
Unfortunately for batch 1 we cannot except escrow, this is something we would like to implement down the line. We suggest either Paypal or credit card for payment protection.

How come you only have 1 post?
I'm more of the silent reader type...

How fast will I get my rig?
Priority for testing will be given in order of sale date, with the first servers aiming to ship a week after arrival to us.

Could you of picked a worse time to try and start selling rigs?
Probably not.

Do you have any further proof this isn't a scam?
https://ibb.co/kr1yk7 https://ibb.co/jbFKsn ready and waiting.

I would like a server with different GPUs
Contact us at the email above and we will let you know if we can do that depending on GPU availability.

The X8R will be our next product, which is currently going through a revision change after prototyping, if you are interested in it, let me know!