Kintex-7 board - good deal? - Page 1
Forum section: electronics / general

author: PhiMX
author_rank: Newbie
timestamp: January 01, 2022, 11:16:53 am
content: Hi there,looking for a high LC-count FPGA board, I came across this dude here:https://de.aliexpress.com/item/1005003668804223.htmlcomparing to other offers of big FPGAs and especially taking into account the recent price spike, I wonder if I am either overlooking something or I am about to fall into a trapI mean, it´s a pretty basic board and it could well be that the chip isn´t new, but come on 120$ for a 326.080 LC-chip on a board? You´d be lucky to find a fake chip for 2x the price. The chip alone is 2000$ on digikey. If something is too good to be true, it probably is, but then again the seller seems reputable and all their other offers seem reasonable.what do you think?

author: woofy
author_rank: Frequent Contributor
timestamp: January 01, 2022, 12:02:12 pm
content: I would guess its a genuine offer. Probably a re-purposed mining rig FPGA. I would be happy to take a punt on it if I needed one.Watch out for the cost of the xilinx licence though.

author: BrianHG
author_rank: Super Contributor
timestamp: January 01, 2022, 12:35:08 pm
content: Well, the FPGA alone is a bit less elsewhere like here:https://www.questcomp.com/part/4/xc7k325t-1ffg676ces9937/433066084?utm_term=xc7k325t-1ffg676ces9937&utm_campaign=aktype0&utm_medium=industry-cpc&utm_source=findchips&utm_content=standardpricingYou cant beat 100$usd.It's like the Arrow DECA board for 37$. 50k logic cell FPGA worth all on it's own ~250$ and with the chip shortage, around 3 months ago, someone out there bought out almost all 1,5k units within a 1-2 days and probably salvaged the FPGAs. It's a shame for those hobbyists who want to learn HDL and now they only have 2 left.

author: voltsandjolts
author_rank: Unknown
timestamp: January 01, 2022, 12:39:59 pm
content: Half of those DECA boards probably went to EEVBlog members, thanks to the thread here at that time

author: asmi
author_rank: Super Contributor
timestamp: January 01, 2022, 11:23:37 pm
content: That chip can consume up to 20 A of power on Vccint rail alone. Do you see anything on that board that looks even remotely like it can output that kind of power? In the description they say: Default power source for board is: 1A@5V DCUnderspecced PDS is an Achilles heel of most of those Aliexpress boards.Also they don't provide a license voucher for this device, so you will need to either buy a full Vivado license (3k$), or source it elsewhere - like buy a Digilent's Genesys 2 board ($1k), which comes with a voucher for a device-locked license of Vivado. This board is the cheapest way I know of getting a license for K325T device, and it can be used for all speed grades and packages (which is a nice bonus).

author: Someone
author_rank: Super Contributor
timestamp: January 01, 2022, 11:27:45 pm
content: Aggressive price points tend to be on the newest generation chips/dev boards. ZCU104 Evaluation Kit comes with a full license device locked to the XCZU7EV part.

author: asmi
author_rank: Super Contributor
timestamp: January 01, 2022, 11:40:00 pm
content: Quote from: Someone on January 01, 2022, 11:27:45 pmThis device is now included into their free Webpack license. Full list of devices included into free license is here:https://www.xilinx.com/products/design-tools/vivado/vivado-ml.html#architectureAnd they do add more devices into free license from time to time, so it's worth keeping an eye on this list if license is something you are concerned about. I wish they would add a full Kintex-7 lineup in this list, as these are plenty of K325/K420 boards which can be acquired for a reasonable money, but license requirement greatly diminish their attractiveness.

author: SiliconWizard
author_rank: Super Contributor
timestamp: January 01, 2022, 11:58:43 pm
content: Quote from: asmi on January 01, 2022, 11:23:37 pmYeah. QMTECH boards are OK for the less power-hungry FPGAs (Spartan 6, Artix-7 35 or 50...) but even for the Artix-7 100 and 200T, as I remember talking in another thread, they are underpowered. Unless of course you use only a tiny fraction of the FPGA, making it basically useless.With no heatsink either. Fun =)

author: Someone
author_rank: Super Contributor
timestamp: January 02, 2022, 10:06:58 am
content: Quote from: asmi on January 01, 2022, 11:40:00 pmInteresting the free coverage has expanded on zynq/mpsoc parts, beyond the resource count of the freely supported "regular" FPGAs (the example K325T being not in the free version).

author: MadTux
author_rank: Frequent Contributor
timestamp: January 02, 2022, 05:00:44 pm
content: Quote from: woofy on January 01, 2022, 12:02:12 pmPiratebay and an $100 laptop with Wifi disabled ;-)

author: colorado.rob
author_rank: Frequent Contributor
timestamp: January 26, 2022, 09:29:01 pm
content: FWIW I just ordered another board from the "HPC FPGA Board Store" on Ali Express ( KC7K325T), along with a couple of the Sipeed Tang Nano 9Ks.