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AMD EPYC Rome 2P Will Have 128-160 PCIe Gen4 Lanes and a Bonus

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Re: AMD EPYC Rome 2P Will Have 128-160 PCIe Gen4 Lanes and a Bonus

#61

Post by justinclift »

wyldfire wrote: post #22
justinclift wrote: post #17

Earlier quoted context omitted.

Hmmm, how many radar pulses need to hit a target to generate video? Sounds potentially irradating... ;) eg: WARNING Don't attempt to image living creatures WARNING

RADAR typically uses microwaves, non-ionizing. Over this area it's bound to be a terribly, terribly small amount of exposure.

Ahhh, no worries.

Just remembering a friend recently telling me about someone who was killed at a work place. Apparently that person walked in front of the main radar array (defense related I think) while it was in operation and just dropped dead instantly. :(

Re: AMD EPYC Rome 2P Will Have 128-160 PCIe Gen4 Lanes and a Bonus

#62

Post by justinclift »

velox_io wrote: post #44
Patrick-STH wrote: post #25

Earlier quoted context omitted.

Here is the easy example: A dual 100GbE NIC requires a PCIe Gen4 x16 slot to run both ports at full speed. Mellanox ConnectX-6 200GbE cards require either 2x Gen4 or 1x Gen5 slot for full dual port bandwidth. Most of the larger NVMEoF nodes we are seeing are using more than one 100GbE NIC. Enterprise SSDs will rapidly fill Gen4 x4 lanes later this year as we start to see them launch alongside more mainstream platform…

Hi Patrick, Before we had M2/U2 NVMe drives, there were quite a few manufacturers making drives that plug straight into the PCIe bus where they could easily access the full 16 lanes, and they still can... Intel seems to be the only ones making PCIe drives (Octane's are funny; they don't look fast only 2000 MB/s, although they do win on latency and random access). Anyway, there doesn't seem to be much demand for that…

> I know we have Infiniband but that has always come at quite a cost, mainly in supercomputers.

Lower end Infiniband (eg 40/56Gb) isn't too expensive these days. Well, that's assuming people aren't paying list price. :)

Re: AMD EPYC Rome 2P Will Have 128-160 PCIe Gen4 Lanes and a Bonus

#63

Post by washadjeffmad »

justinclift wrote: post #61
wyldfire wrote: post #22

Earlier quoted context omitted.

RADAR typically uses microwaves, non-ionizing. Over this area it's bound to be a terribly, terribly small amount of exposure.

Ahhh, no worries. Just remembering a friend recently telling me about someone who was killed at a work place. Apparently that person walked in front of the main radar array (defense related I think) while it was in operation and just dropped dead instantly. :(

This happened to a former schoolmate of mine with a pacemaker when strong EM equipment was turned on near them.

The people on site had no idea he had one and attempted to administer CPR, but they wouldn't have been able to detect his pulse, regardless.

Imagine how it looked to the people who never found out and the version of the story they might still be telling others.

Re: AMD EPYC Rome 2P Will Have 128-160 PCIe Gen4 Lanes and a Bonus

#64

Post by dual_basis »

consp wrote: post #2

Can someone enlighten me with some information about application requiring the full 16x PCIe gen4 bandwidth per slot (or 32x gen3 for that matter)? I can imagine some HPC GPU solutions but other than that what requires the thoughput? There is obviously a market for this as both giants are building platforms.

What about a bunch of NVMe drives?

Re: AMD EPYC Rome 2P Will Have 128-160 PCIe Gen4 Lanes and a Bonus

#65

Post by Yetanfou »

justinclift wrote: post #61
wyldfire wrote: post #22

Earlier quoted context omitted.

RADAR typically uses microwaves, non-ionizing. Over this area it's bound to be a terribly, terribly small amount of exposure.

Ahhh, no worries. Just remembering a friend recently telling me about someone who was killed at a work place. Apparently that person walked in front of the main radar array (defense related I think) while it was in operation and just dropped dead instantly. :(

At the 1933 World’s Fair in Chicago, Westinghouse demonstrated a 10-kilowatt shortwave radio transmitter that cooked steaks and potatoes between two metal plates [1]. In 1946 a Raytheon engineer named Robert Spencer "...was visiting a lab where magnetrons, the power tubes of radar sets, were being tested. Suddenly, he felt a peanut bar start to cook in his pocket. Other scientists had noticed this phenomenon, but Spencer itched to know more about it. He sent a boy out for a package of popcorn. When he held it near a magnetron, popcorn exploded all over the lab. Next morning he brought in a kettle, cut a hole in the side and put an uncooked egg (in its shell) into the pot. Then he moved a magnetron against the hole and turned on the juice. A sceptical engineer peeked over the top of the pot just in time to catch a face-full of cooked egg. The reason? The yolk cooked faster than the outside, causing the egg to burst..." [2]. This discovery led to a patent application for "the use of microwaves to heat food", a concept which was eventually realised in the "Raytheon RadaRange" series of microwave ovens [3].

[1] https://en.wikipedia.org/wiki/Microwave_oven#/media/File:Coo...

[2] https://spectrum.ieee.org/tech-history/space-age/a-brief-his...

[3] https://en.wikipedia.org/wiki/Microwave_oven#/media/File:NS_...

Re: AMD EPYC Rome 2P Will Have 128-160 PCIe Gen4 Lanes and a Bonus

#66

Post by geokon »

kilo_bravo_3 wrote: post #14
consp wrote: post #2

Can someone enlighten me with some information about application requiring the full 16x PCIe gen4 bandwidth per slot (or 32x gen3 for that matter)? I can imagine some HPC GPU solutions but other than that what requires the thoughput? There is obviously a market for this as both giants are building platforms.

Off the top of my head this would be great for massive enterprise VDI installations and game streaming services (which is just VDI by another name), ML, AI applications, and NVMe storage. Personally, this will be good for me because everything I do is bandwidth-starved. I'm not a radar scientist but I am a systems engineer supporting radar scientists working on air- and space-based Synthetic Aperture Radar (SAR) syst…

A bit off topic, but where can I find details of the math behind SAR? In my last job I worked on radar systems and I was always curious about SAR. However all the information I found was high level descriptions. There was even some MIT course available on it but they too skipped/avoided the math involved

(Im curious to see if I can apply similar techniques to audio)

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