Which is better as a Virtual host? AMD FX-8370E vs i7-4790K

[hasu]

Which CPU would be a better candidate to serve as a Virtual Machine host on Linux OS? Currently I am using VirtualBox but I might consider KVM in the future. Both these CPUs run at similar frequencies. AMD has 8 cores while Intel has 4 cores with hyper-threading.

I want to run (at least) the following Virtual Machines simultaneously:

Linux Mint Desktop 64bit
Ubuntu Server 64bit (mainly for database/web server)
Windows XP (or Vista) 32bit

Host machine will have 16G RAM. Each Virtual Machine is configured as 2 CPU machines. Virtual Machine Disk images are stored on SSDs (grow as needed, not pre-allocated).

Most used applications on the Virtual machines are Lazarus, Netbeans, Eclipse, GIMP or other image editing and Raw Image conversion tools -- so Desktop/GUI response is very important.

Any comments?

Thanks!

 

[jhu]

The 4790k has better single thread performance than the FX. That will make GIMP, Eclipse, etc. run faster. But it's about $100 more. FX can use ECC RAM if you can find a board that supports it and if that's important to you.

 

[Phynaz]

Jhu has it right.

 

[DrMrLordX]

OP, I would poke around on Phoronix. They have some good VM benchmarks over there. There are some situations where VM performance will swing wildly in favor of the 8370E, and some in favor of the 4790k. In terms of raw processing power, the 4790k will be the more powerful CPU, though the 8370E will strut its stuff once the thread count starts to climb.

Since you have mentioned both an FX processor and a k-class processor, I must ask: are you planning to overclock?

 

[hasu]

OP, I would poke around on Phoronix. They have some good VM benchmarks over there. There are some situations where VM performance will swing wildly in favor of the 8370E, and some in favor of the 4790k. In terms of raw processing power, the 4790k will be the more powerful CPU, though the 8370E will strut its stuff once the thread count starts to climb.

Since you have mentioned both an FX processor and a k-class processor, I must ask: are you planning to overclock?

No plan to overclock now.

I already bought FX-8370E and I am impressed. I ran Phoronix benchmark for Timed Linux Kernel Compilation and 8370E scored 150, same as that of my 1100T (on a different motherboard). As per Phoronix, i7-4790K's score for the same test should be just under 100, which is much better. My concern is that i7 has only 4 cores and I am not sure if HT will help with VM at all.

 

[DrMrLordX]

HT should help. The problem will come from multiple little tasks that do not necessarily require much CPU time individually. That is when you want more thread-handling capability. Technically the 4790k has the capability to handle threads just as well as an FX. Regardless, I think the FX will serve you well when you run that web server/db.

Have fun with the FX regardless. If you ever do start messing with clockspeeds and voltages, you will find that it will probably reach 4.4 ghz on surprisingly little voltage.

 

[justanotherboy]

You said that you require GIMP in the desktop, are you going to use IOMMU to pass the GPU? Or what are your plans to pass the GPU?

 

[hasu]

You said that you require GIMP in the desktop, are you going to use IOMMU to pass the GPU? Or what are your plans to pass the GPU?

Right now I run GIMP and UFRaw on the host itself.

IIRC I turned on all Virtualization settings in VirtualBox including VT-d/IOMMU, even on my current Phenom II X6-1100T. I have not tested the Virtual Machines with and without that setting to see the difference. That is something I may have to experiment with. Do you have any recommendation?

Thanks

 

[justanotherboy]

Vt-d/IOMMU allow to pass a DMA device (USB, PCI, Ethernet) to the vhost. You could allow a guest to use a graphics card (if you had a headless Linux install or 2+ cards). I know Xen, Hyper-V, and VMware support this feature; KVM I'm not sure and last time I checked VirtualBox doesn't support it.

Also for Vt-d/IOMMU you need a CPU AND Mobo that support Vt-d/IOMMU, several consumer Mobos doesn't support Vt-d. Here is a nice thread to check if you seriously plan to use this feature. http://forums.anandtech.com/showthread.php?t=2326402&page=2

There is another option to pass the the GPU for Intel but is in very early stages and only for Xen, it's called XenGT, there are plans to implement it on KVM also.
https://01.org/xen/blogs/srclarkx/2013/graphics-virtualization-xengt
http://lists.xen.org/archives/html/xen-devel/2013-09/pdf4ObWP0JtcP.pdf

Hope this helps

 

[ShintaiDK]

IOMMU is also known officially as AMD-Vi.

The biggest problem with Vt-D/AMD-Vi support is the lack of BIOS support.

 

[hasu]

Vt-d/IOMMU allow to pass a DMA device (USB, PCI, Ethernet) to the vhost. You could allow a guest to use a graphics card (if you had a headless Linux install or 2+ cards). I know Xen, Hyper-V, and VMware support this feature; KVM I'm not sure and last time I checked VirtualBox doesn't support it.

Also for Vt-d/IOMMU you need a CPU AND Mobo that support Vt-d/IOMMU, several consumer Mobos doesn't support Vt-d. Here is a nice thread to check if you seriously plan to use this feature. http://forums.anandtech.com/showthread.php?t=2326402&page=2

There is another option to pass the the GPU for Intel but is in very early stages and only for Xen, it's called XenGT, there are plans to implement it on KVM also.
https://01.org/xen/blogs/srclarkx/2013/graphics-virtualization-xengt
http://lists.xen.org/archives/html/xen-devel/2013-09/pdf4ObWP0JtcP.pdf

Hope this helps

Looks like IOMMU/VT-d is going to bring out big improvements for graphics. By any chance do you know of any MicroATX motherboard which supports this for AMD or Intel? Thanks!

 

[justanotherboy]

IOMMU is also known officially as AMD-Vi.

The biggest problem with Vt-D/AMD-Vi support is the lack of BIOS support.

Thanks for the clarification

Looks like IOMMU/VT-d is going to bring out big improvements for graphics. By any chance do you know of any MicroATX motherboard which supports this for AMD or Intel? Thanks!

For the 4790K I'm not aware of any Mobo that support it. Usually the Qx7 series chipset is the one that supports Vt-d but there isn't a Q chipset for 9 series. For the AMD part I don't know.

Reading the thread that I copied early, it seems it is possible to do this on the PCIe slot connected directly to the CPU, but as Shintai says, you need support for that and several times the vendor is clueless about it. Also note you need Function Level Reset (FLR) in the graphic card to pass it to the vhost.

I haven't tested yet but is one of my 'projects' for the holidays

 

[hasu]

Thanks for the clarification



For the 4790K I'm not aware of any Mobo that support it. Usually the Qx7 series chipset is the one that supports Vt-d but there isn't a Q chipset for 9 series. For the AMD part I don't know.

Reading the thread that I copied early, it seems it is possible to do this on the PCIe slot connected directly to the CPU, but as Shintai says, you need support for that and several times the vendor is clueless about it. Also note you need Function Level Reset (FLR) in the graphic card to pass it to the vhost.

I haven't tested yet but is one of my 'projects' for the holidays

Thanks! I have to read more about that to see if that is something I can do now.

 

[ShintaiDK]

Lots of Z series boards etc supports VT-D.

Specially AsRock is good for VT-D support.

 

[Abwx]

The biggest problem with Vt-D/AMD-Vi support is the lack of BIOS support.

Still trying to mislead the general public..?.

Do they need Bios support if the feature is enabled anyway.?.

RedHat opinion on the matter :

AMD-V extensions cannot be disabled in the BIOS and should already be enabled.

https://access.redhat.com/documenta...rtualization_hardware_extensions_in_BIOS.html

 

[ShintaiDK]

Still trying to mislead the general public..?.

Do they need Bios support if the feature is enabled anyway.?.

RedHat opinion on the matter :



https://access.redhat.com/documenta...rtualization_hardware_extensions_in_BIOS.html

We are talking about AMD-Vi and VT-D. Not VT-X or AMD-V.

 

[Abwx]

We are talking about AMD-Vi and VT-D. Not VT-X or AMD-V.

900 chipset + FX/X6 or any A series APU.

http://en.wikipedia.org/wiki/List_of_IOMMU-supporting_hardware

Subject has been discussed in a previous thread :

http://forums.anandtech.com/showthread.php?t=2301512

 

[JoeRambo]

A quote from that same page You have linked:

Please note that just because a motherboard uses a chipset that supports IOMMU does not mean it is able to and the bios must have an ACPI IVRS table to enable the use of it.

 

[Headfoot]

Anyone who says VT-D or AMD-Vi categorically works for all CPUs that support it has never tried to get VT-D or AMD-Vi working in the real world

 

[dave_the_nerd]

If you're not overclocking, you might consider a Xeon. They're in the same pricerange as the 4790K, and support ECC is you're so inclined. (as well as Vt-d.)

 

[ShintaiDK]

Anyone who says VT-D or AMD-Vi categorically works for all CPUs that support it has never tried to get VT-D or AMD-Vi working in the real world

^^ This.

 

[DrMrLordX]

fwiw, my A88x-Pro has an IOMMU option in the UEFI. That doesn't help the OP though.

 

[Cerb]

Having the option doesn't mean it'll work, though, because outside of servers and workstations, it's rarely tested. My B85 board has it, but I couldn't get an OS up and running using it (I only tried because I saw the feature and have spare HDDs, so no loss or anything...).

In any case, virtual video going through ABI/API wrappers works quite well, most of the time, especially for Linux guests to Linux hosts.

 

[hasu]

Can VT-d share a video card between multiple guests?

 

[dave_the_nerd]

Can VT-d share a video card between multiple guests?

No. Vt-d is essentially a passthrough - it hands off control of a PCI-E device to a specific VM.

I have heard about other techs that will share render between guests, but I didn't get any specifics.