virtualbox.org

Hi loukingjr and others;

Thanks for your replies. I attached VBox.zip.

tono777

Couple of things:
- Where is drive P:\, maybe a network share?
- You have installed "Actual Window Manager" which is causing VBox to reject "aimemb64.dll". Which by the way is loading from drive Z:\. Where is that drive?

> Where is drive P:\, maybe a network share?

Yes, it is a network share.

> You have installed "Actual Window Manager" which is ... Where is that drive?

I deleted all network share drives and stopped Actual Window Manager, but Windows 10 64bit guest still slow. I attached the new VBox.log.

You still have the guest defined with 4 virtual CPUs, which is way too much for your dualcore CPU.
Try again with only one virtual CPU.

Martin wrote:You still have the guest defined with 4 virtual CPUs, which is way too much for your dualcore CPU.
Try again with only one virtual CPU.

Unless, I really missed something, tono777's logs says otherwise:

00:00:03.739315 CPUM: Logical host processors: 12 present, 12 max, 12 online, online mask: 0000000000000fff
00:00:03.739447 CPUM: Physical host cores: 6

@tono

tono777 wrote:I deleted all network share drives

How can you delete all network shares since your virtual hard drive is residing on a network share? Have you checked the network traffic on the host? Disk access times on host and guest?

And by the way, you still have not gone in the Task Manager in your guest to actually pinpoint the offending process. And on top of that I still need to see some hard evidence or a definition of "slow".

socratis wrote:Unless, I really missed something, tono777's logs says otherwise:

00:00:03.739315 CPUM: Logical host processors: 12 present, 12 max, 12 online, online mask: 0000000000000fff
00:00:03.739447 CPUM: Physical host cores: 6

Seems I didn't read that far, I only saw the line which would be a dualcore CPU.

Further down it shows the correct sixcore model "Intel(R) Core(TM) i7-5930K"

Interesting. As socratis points out, my host PC has i7-5930k which has 6 cores and 12 threads. So 4 CPUs for VM should be fine (Windows 7 guest is okay with 4 CPUs). But if I reduce the number of CPU to 1 or 2 for Windows 10 guest, it obviously faster!!

(1) 4 CPUs : VM start up and browser start up both are slow.
(2) 2 CPUs : VM start up is slow, but browser start up is fast.
(3) 1 CPU : VM start up and browser start up both are fast.

I didn't actually measure anything, but you can easily tell when it's slow.
Above results show that Windows 10 64 bit geust can't handle multi cpu/core very well ?
Anyway I will use it with 2 cpus (1 cpu is risky because if an application fell in hang with 100%cpu, I will not be able to do anything).

FWIW, it seems to me after several posts mentioning CPUs with either more than 4 cores or more than 1 CPU with 8 cores or more, there is an issue running more than 2 cores on the guest. I don't know if it's the guest OS, the host OS, VirtualBox or some combination, but once someone assigns more than 2 CPUs things slow down for many.

@tono777, can you see how your Windows 7 guest runs with 2 CPUs?

> tono777, can you see how your Windows 7 guest runs with 2 CPUs?

I don't see any slowness. But for windows 7 32 bit guest, even with 4 cpus, it still good compare to windows 10 64 bit guest.
Since I don't have windows 7 64 bit, I can't really compare the difference between windows 7 and windows 10...

Would you say running your Windows 7 guest on 2 CPUs is as fast as running 4 CPUs? If so, doesn't seem to be a reason to run 4. Also, is your Windows 7 guest also assigned 8 GBs of RAM?

Something I find interesting (maybe just for Mac users), according to GeekBench, the latest 27" Retina iMac scores the highest of any Apple computer running a 32bit or 64bit single core test. However, it is 11th running 32bit multi-core and 9th running 64bit multi-core tests.

What that says to me is the number of cores run is certainly not the whole story.

> Would you say running your Windows 7 guest on 2 CPUs is as fast as running 4 CPUs? If so, doesn't seem to be a reason to run 4.

Yes, I feel no difference between windows 7 on 2 cpus and 4 cpus. That's because I only seeing VM startup and web browsing which is not heavy cpu load. I just changed to 4 because I upgraded my host pc from i5-2500k to i7-5930k which has a lot more cpus for VMs.

> Also, is your Windows 7 guest also assigned 8 GBs of RAM?

No, Windows 7 guest is 32bit so I assigned only 3GB. Because I needed more memory, I used 64bit for Windows 10 and assigned 8gb memory.

> What that says to me is the number of cores run is certainly not the whole story.

I changed to 2 cpus and it works better. Thanks a lot for your help!!

The fact that your Windows 7 guest is 32bit could account for the difference in speed over your Windows 10 64bit guest.

The way I look at the entire "How many cores should I run on my guest?" question is, run what gives you the best performance overall no matter how many cores your host has. Seems simple enough.

I'm glad things worked out.

My philosophy is to install one CPU in a vm and see how it goes. If it seems to struggle, try two, but don't automatically expect an improvement. There are too many variables.

Usually putting the .vdi on a faster drive is a better bet for most jobs.

All my guests running on Intel i7s (4 cores/8 threads) up through the Skylake 6th generation are set to 2. My two machines with Intel M CPUs (2 cores/4 threads) are also set to 2. For some reason they work fine that way.

I like 2.