High Internet Explorer CPU on Flash site in Citrix

Hello - we are noticing very high Internet Explorer CPU usage on our Citrix servers.  Currently we have a small farm (5 Servers) offering a published desktop to remote site and home users.  Generally speaking we observe poor performance, high CPU and Memory around the same time everyday.  Event logs and task scheduler do not indicate any issues.  

100% of the time the culprit was either a IE or Chrome process consuming 70 to 80% CPU.  Lately, i have been able to isolate the problem to a couple of user sessions and even asked those users what sites they were visiting when the problems occurred.  

Pretty consistently I heard, either www.nydailynews.com or www.yahoo.com

Over the past month we have noticed a spike in these types of issues.  

IE 11
(5) Virtual Machines:  Citrix XenApp 6.5 / Server 2008 R2
Virtual Machine:  16GB Memory / 2 vCPU
Average 10 User Sessions per Citrix Server
Citrix Receiver 14.2
VmWare VCenter 5.5

After a ton of research i feel like the ultimate trigger is Flash and possibly the need for an additional 2vCPU  per server.

1.  Do you recommend i provision and additonal 2vCPU?
2.  Would HDX Redirection / offloading help in this situation?
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Dirk KotteSECommented:
if your hosting subsystem don't use the real existing CPU's you may add extra vCPU.
Flash redirection delegate the work to the workstation. (you need windows workstations and a current receiver I think)
This should help relieving the servers.
But you have to open the firewall/Proxy, so workstations can access the content directly.

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LenCepedaAuthor Commented:
Thank you DKOTTE.  The citrix servers are VM's on VMware ESXi Hosts.  We have provisioned 2vCPU's per server but according to a number of forums/blogs it is standard practice to assign 4vCPU's per VM.  We don't have much capacity so I am reluctant to throw additional resources to address a problem.  

Ultimately, I blocked the Daily News Website and that had an immediate impact.  Also, I disabled the Windows Update Service (WUASERV Process) which was also causing some of the performance issues.  Right now we are working well so I have some more time to research and test Flash Redirection.  Thank you
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