AMD 1800x w/AM4 or Intel i7-7820X w/X299?


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I'm planning my first build to use with Un-Raid and I'm looking for guidance/wisdom from you guys.  I'm planning to use the setup for the following...

 

  • Containers
    • Plex with three consecutive streams
    • Sonarr, Radarr, Sabnzbd, and a few others
  • Two or Three Windows 10 VMs

 

I understand there are known issues with going the AMD route but I wasn't sure if I might be facing issues as well if I went with Intel's new chipset. If you were planning a new build, would you go Intel or AMD or something different all together?

 

Any help you can give is much appreciated!

Edited by MrMoosieMan
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depends on your vm use case. if you plan to do hardware passthrough in your vms make sure to look into the iommu grouping situation on ryzen. maybe the latest agesa bios solves some hickups?! estimate how many pcie lanes you will need.

 

intels x299 is not yet released. likely there will be less iommu issues since the platform is very similar to the previous one. however 

intel may change things to keep server features more seperate to their upcoming xeon products. if you have the time, I suggest you wait a bit until first hand reviews are available.

 

I just did a E5-1620v4 build. very happy with the performance and no bottlenecks. id love to have AMD cores + plenty of pcie but Core i9-7900X will get a whole lot more expensive 

maybe threadripper (AMDs HEDT) platform will solve the iommu and pcie limitations. I consider to switch to AMD by then

 

 

 

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On 6/13/2017 at 8:12 AM, unrateable said:

depends on your vm use case. if you plan to do hardware passthrough in your vms make sure to look into the iommu grouping situation on ryzen. maybe the latest agesa bios solves some hickups?! estimate how many pcie lanes you will need.

 

Is there any downside to using the ACS override feature?  Once enabled, my IOMMU groupings are very, very favorable for VM usage.  I am currently passing through my GPU, and also a USB 3.0 port from the motherboard.  ASUS Prime X370-PRO motherboard, and the Ryzen 1800X (you can probably do very well with a 1700 though!)

 

- Bill

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10 hours ago, ufopinball said:

 

Is there any downside to using the ACS override feature?  Once enabled, my IOMMU groupings are very, very favorable for VM usage.  I am currently passing through my GPU, and also a USB 3.0 port from the motherboard.  ASUS Prime X370-PRO motherboard, and the Ryzen 1800X (you can probably do very well with a 1700 though!)

 

- Bill

 afaik there are certain stability and security concerns due to overlaps in the address space and resulting data corruption and potential illegal access.

as the word says it overrides a barrier and its a quirk to improve the lack of proper isolation for hw that is capable but not flagged as such. the ´ACS forces the system to `assume´ separation of io operation works. once devices that are physically in the same group on the same port, root or downstream they may end up using the same ressources - then things can get messed up.

 

I suspect, in your use case with your specific hw setup you have not yet seen any critical io adress overlaps.

that doesnt mean they dont exist. what overall impact can it make ? hard to tell. I worry, others not. But was one of the reasons to go with an E5 for the time being. 

 

[edit: a reply from a discussion a while ago, from a developer to Alex Williamson who wrote the ACS override patch

" But the possibility of compromise is probably even more serious, because there would be no crash at all, and we'd have no indication that VM A read or corrupted data in VM B. I'm very concerned about that, enough so that it's not clear to me that an override belongs in the upstream kernel at all."

source ]

 

I do remember some forum discussion a while ago where wendel form level1tech had to use different GPUs in order to kind of "confuse" the io(mmu) control in a way that things would somehow work at the same time. [it may not be related ]

 

Out of curiosity: did you run benchmarks ?  - while your host is fully utilizing the remaining hw io ressources and - while your host is idle ?    

 

I would be happy to see more ryzen users sharing their iommu experiences. so far I found you are one of very few people with a very positive feedback. I may have missed some others ?!

 

cheers

 

Edited by unrateable
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22 hours ago, unrateable said:

Out of curiosity: did you run benchmarks ?  - while your host is fully utilizing the remaining hw io ressources and - while your host is idle ?    

 

I may have, but it's been awhile.  I originally ran Cinebench and Blender.  Are there other benchmarks you suggest?  Note that my GPU isn't a gaming model.

 

As for "utilizing other resources" ... is there an easy way to do this?  I can start a second VM, assign it all remaining CPU cores, and run Prime95 there.  Does that cover what you are asking?

 

- Bill

 

 

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On 22.6.2017 at 10:36 AM, ufopinball said:

I may have, but it's been awhile.  I originally ran Cinebench and Blender.  Are there other benchmarks you suggest?  Note that my GPU isn't a gaming model.

As for "utilizing other resources" ... is there an easy way to do this?  I can start a second VM, assign it all remaining CPU cores, and run Prime95 there.  Does that cover what you are asking?

 

no, no suggestions in particular, I am afraid. 

 

assigning cpu cores wont do it.

I guess if you want to dive into the field testing rabbit hole then you must use as many pcie lanes with as much data load as possible all at the same time, including the pcie slots and the pch connected onboard hubs (usb controller, onboard sound, phys.+virt NICs). then see if any glitches and hiccups occur. instabilities eg system crashes would be easy to recognize but it will be a nightmare to identify smaller data corruptions and verify bus adress space mapping violations.

 

as long as your ryzen system runs well as you describe, no real need to mess it up. acs conflicts may be very rare events afterall depending on the individual setups and workloads. however if you encounter unexplainable system behaviour while the acs patch is enabled it would be my very first thing to investigate.

 

 

Edited by unrateable
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Thanks for the info on the ACS override, I was not aware that there were such problems.  Will keep an eye on it, but so far my Ryzen system has been very stable.  I would run more tests, but it's also a production system (runs several websites, and Plex for my family) so I'm not at liberty to take it down to perform testing at the level you describe.

 

- Bill

 

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