About RAM and mobo

[satimis]

Hi

I have a Phenom II X4 955 box running 8G RAM. Now I'm planning building a Phenom II X6 box running 16G RAM. But the 4G module/stick is very expensive, not easy to find. However most mobo can take max 4 sticks. I can't find mobo board on market except server taking 8 sticks. Any advice? TIA

B.R.
satimis

[wuttz]

this: Opteron 6128 [MPN: OS6128WKT8EGO]
and this: SUPERMICRO MBD-H8SGL-F-O [Model MBD-H8SGL-F-O]
ddr3-1333/ECC registered: KVR1333D3D4R9SK2/8G

1090T has six cores and dual channel ram only.
the 6128 has eight cores. with quad channel ram.
you can get 2 sets(4 sticks) of the 4GB ram.
add 2 more sets if you need more ram in the future.

[satimis]

this: Opteron 6128 [MPN: OS6128WKT8EGO]
and this: SUPERMICRO MBD-H8SGL-F-O [Model MBD-H8SGL-F-O]
ddr3-1333/ECC registered: KVR1333D3D4R9SK2/8G

1090T has six cores and dual channel ram only.
the 6128 has eight cores. with quad channel ram.
you can get 2 sets(4 sticks) of the 4GB ram.
add 2 more sets if you need more ram in the future.

Hi,

Thanks for your advice.

Opteron is for server. I'm not prepared to build a server.

I have a Phenom II X4 955 box here running 8G RAM. Therefore I expect adding more RAM on the new box. Besides I will use the new box as virtual machine running >30 guests (VM) on it.

Now the old box Phenom II X4 955 is also a Virtual Machine running >15 guests(VM) on it, Linux/Windows. I have no idea if all guests are running at the same time whether RAM will be sufficient?

B.R.
satimis

[mdk777]

Yes, only server boards (on AMD) have more than 4 slots.

However, 4 GIG sticks are coming down in price.

16 GIG for $500
http://www.newegg.com/Product/ProductLi ... x%204GB%29

While $31/GB is not dirt cheap, for this kind of memory density it is not bad.

Server is of course more appropriate platform for running massive # of VM.

[wuttz]

you will definitely need more than 8GB for running >30 VM's.
how much ddram will you allocate per linux/windows guest?
windows as a host takes at least 2GB for decent performance.
linux can get by with 1GB. i'm assuming you need to allocate just as
much per guest OS? (i.e. 2GB/windows guest, 1GB/linux guest)

2GBx15windows guests = 30GB
1GBx15 linux guests = 15GB

32GB should be a good spot if the guest OS arent at full-load all the time.

[satimis]

Yes, only server boards (on AMD) have more than 4 slots.

However, 4 GIG sticks are coming down in price.

Hi mrgreen,

Thanks for your advice.

The price of 2x4G (8G) dual channel RAM is going down. I do hope when I start to shop (at least 30 days later) I may have a better price.

Server is of course more appropriate platform for running massive # of VM.

Agreed. But I use this box for testing software NOT for production. Therefore I hope to lower its cost.


B.R.
satimis

[satimis]

you will definitely need more than 8GB for running >30 VM's.
how much ddram will you allocate per linux/windows guest?
windows as a host takes at least 2GB for decent performance.
linux can get by with 1GB. i'm assuming you need to allocate just as
much per guest OS? (i.e. 2GB/windows guest, 1GB/linux guest)

2GBx15windows guests = 30GB
1GBx15 linux guests = 15GB

32GB should be a good spot if the guest OS arent at full-load all the time.

Hi wuttz,

Now I allot 256MB for Linux server and 512MB for Linux workstation. The former is without X. They are now working without problem. For Windows I allot 1G. The host of this virtual machine runs 64 bit Ubuntu 10.04 workstation with Sun VirtualBox and KVM/QEMU as virtualizer. They are NOT running simultaneously. One is running another stops. ON the present kernel they can't run concurrently. But it is possible on the new kernel which is coming soon.

I have 32bit and 64bit WinXP, Win7, Vista running on this box. Most the time they are not all running together. All of them are now working happily on this box.

B.R.
satimis

[abinstein]

Now I allot 256MB for Linux server and 512MB for Linux workstation. The former is without X. They are now working without problem. For Windows I allot 1G. The host of this virtual machine runs 64 bit Ubuntu 10.04 workstation with Sun VirtualBox and KVM/QEMU as virtualizer. They are NOT running simultaneously. One is running another stops. ON the present kernel they can't run concurrently. But it is possible on the new kernel which is coming soon.

I have 32bit and 64bit WinXP, Win7, Vista running on this box. Most the time they are not all running together. All of them are now working happily on this box.

I think you'll need a server box. Desktop mobos and cpus are not designed for the workloads that you have.

BTW, running 30 VMs on 6 cores will definitely impact your performance, especially if they run concurrently. Just the higher TLB and L1D misses will bring performance to a crawl no matter how much memory you throw at it. This is true even with the nested TLB feature. Imagine you have a 12-cores Opteron. the increased TLB and cache size will more than make up for the slower clock, and perhaps with lower power consumption (with increased stability--if either is important to you).

EDIT: Oh I just saw you said this box is for testing software, and the VMs do not run together. In that case performance is probably not as important to you. But still it won't hurt to use an Opteron, especially since the 8-core ones are in the same price range as Thubans. With a server board and 8 dimm slots you'll have much more freedom to add even more VMs to the machine.

[satimis]

Now I allot 256MB for Linux server and 512MB for Linux workstation. The former is without X. They are now working without problem. For Windows I allot 1G. The host of this virtual machine runs 64 bit Ubuntu 10.04 workstation with Sun VirtualBox and KVM/QEMU as virtualizer. They are NOT running simultaneously. One is running another stops. ON the present kernel they can't run concurrently. But it is possible on the new kernel which is coming soon.

I have 32bit and 64bit WinXP, Win7, Vista running on this box. Most the time they are not all running together. All of them are now working happily on this box.

I think you'll need a server box. Desktop mobos and cpus are not designed for the workloads that you have.

BTW, running 30 VMs on 6 cores will definitely impact your performance, especially if they run concurrently. Just the higher TLB and L1D misses will bring performance to a crawl no matter how much memory you throw at it. This is true even with the nested TLB feature. Imagine you have a 12-cores Opteron. the increased TLB and cache size will more than make up for the slower clock, and perhaps with lower power consumption (with increased stability--if either is important to you).

EDIT: Oh I just saw you said this box is for testing software, and the VMs do not run together. In that case performance is probably not as important to you. But still it won't hurt to use an Opteron, especially since the 8-core ones are in the same price range as Thubans. With a server board and 8 dimm slots you'll have much more freedom to add even more VMs to the machine.

Hi abinstein,

Thanks for your advice. I have been running AMD cpu since K6. I have single core (1G RAM), X2 (4G RAM) and X4 (8G RAM) boxes here. The single core box will phase out soon.

Actually there is no clear dividing line between server and desktop workstation. My rule in considering building a new box focusing on its usage first. Budget comes after it. It is NOT my interest building a new box with feature/function equal or inferior to the existing boxes. Nor I'll reuse the old components.

I haven't built multi-cpu box before. Also it is my interest to build such a box. I'm running virtualization on the boxes. There are many cloned guests, i.e. having several Ubuntu/Debian/Fedora guests on the same box. Each guest has its own testing environment. Not all guests will run concurrently. I also have Windows guests such WinXP, Vista, etc. for testing the cross platform packages built on Mono. But the packages are NOT sizable with test lasting for a short span.

What I'm most concerned is whether to get a 40 tons truck to carry 4 ton load wasting fuel and the cost to purchase a big truck. Besides the price of opteron and its mobo are always much higher than a consumer cpu because of the demand. The retailers won't reduce price to compete.

Anyway lot of thanks for your advice.

B.R.
satimis

[skrubol]

Besides the price of opteron and its mobo are always much higher than a consumer cpu because of the demand. The retailers won't reduce price to compete.

Have you priced Opterons recently? I think you might be surprised.

[abinstein]

Besides the price of opteron and its mobo are always much higher than a consumer cpu because of the demand. The retailers won't reduce price to compete.

Have you priced Opterons recently? I think you might be surprised.

I think the single-socket G34 platform is what you may want. wuttz posted the mobo in his earliest reply. (His link to the Opteron 6128 seems not to work now.
At NewEgg, the 8-core Opteron 6134 plus the supermicro MB is about $800. This is even less than the price of a combo of, say, Core i7 950 plus any good mobo.)

And this allows you to increase total memory size to 32GB. The least benefit is that you can double the memory allocation to each VM without worrying about performance.