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Memory requirements


Hi, the system administration of my company asked me the requirements to run your viewer. He want to put the viewer on a stand-alone server where it will be recalled by the various applications that will need it. We use the viewer and iis servers.
In particular he would need to know how much ram to dedicate… We use all the types that your viewer is able to view, mostly eml file with minum dimension of 10MB.

Can you help me?




The only requirement that we have is .NET 2.0 (or greater) or Mono installed and it depends on your requirements that how fast you would like to open and view the documents. A server with high specs (i.e. memory and processor) will result in more improved performance of the application, however, it all depends on how the application will be used.


The problem arose when, in a very high usage environment, the viewer application pool reached the amount of memory allocated to 10GB and no longer responded.
In this context the use of the CPU used by the application pool was very high.
From our experience this behavior would seem to be a memory leak of the component.
Are you aware of these problems? Have you got to experience behavior with high usage? (about 100 users connected).




The CPU and memory utilization depends on the content and size of the documents that you are rendering/viewing in your application as well as the number of users using the application. The larger documents may consume more resources and it may affect the performance if the payload exceeds the capability of the machine. However, please share your working environment (i.e. OS) along with the following details so that we can investigate if there is any issue regarding the memory leak:

  • Standalone console application (source code without compilation errors) that will help to reproduce the behavior.
  • Version of the API you are using.
  • Sample documents.


Hello, the problem we manifested is difficult to reproduce, as we should simulate the access (even simultaneous) of n users to the same site of the viewer.
I have however tried to simulate the problem in the site that I am attaching to: this will create 20 instances of the viewer, opening it in 10 different tabs you will have more or less the same load that we find from one of our customers.
As you can see from the task manager the cpu will be very high and constant as the memory of the w3wp.exe process (we use an iis server). Once the loading is finished, then, there is no real release of the memory used. This means that with intensive use, the memory goes to occupy even 10GB and the use of the CPU remains at 100% for several minutes.
We currently use version 17.12 of Groudocs.Viewer.dll, the demo files can be found in the App_Data folder. I have not attached the license file, you will need to copy your valid license file to the App_Data folder.

Here the link to the project:

I hope I was clear.

kind regards



Thanks for providing the details. We shall investigate your scenario and share the outcomes with you shortly.



The application you have shared is an ASP.NET web application that renders the document and displays it in the browser. It would not be incorrect if we say that there are multiple factors that may be involved in resource consumption, for example, how the API is used in the application, the other operations that are being performed in the application, and so on. Therefore, to better analyze the memory and CPU consumption of the API and to check if there is any memory leak, we should use a standalone application.

For this, we have created this sample console application that can be used to analyze the memory and CPU consumption of the API while it renders multiple documents simultaneously. You can try it at your end by putting your eml files in the bin/debug/storage folder. To meet the workload of your scenario, you can vary the number of files in the storage folder. Please try and share your outcomes with us.


I managed to replicate the problem, I’m looking for a way to show you a report.
I’ll let you know you as soon as possible.

Kind regards





Hi, I was able to simulate the problem using 200 files. In the upload folder you will find the files we used, in particular we used:
10 copies of the DOC_30MB.doc file
5 copies of the EML_60MB.eml file
50 copies of the EML_2,3MB.eml file
30 copies of the DOCX_9.9MB.docx file
30 copies of the EML_1,8MB.eml file
35 copies of the file ODT_212KB.odt
40 copies of the DOCX_6Kb.docx file
In the folder you will also find the memory and cpu reports that we have recorded: we have reached over 7GB of memory with a percentage of use of the cpu close to 99% and as you can see, the memory is very difficult to be freed.
If you think that from our customer there are at least 150 users connected simultaneously and that they continue to view documents, you can well understand the saturation level at which the machine arrives.

Here the files and the reports:




Thanks for sharing the details. Would you please share with us the specifications (OS name and version, RAM and CPU etc.) of your server machine where you have replicated the issue using the console application?


Yes, Windows Server 2016 Standard, 16GB RAM, i7 6700K.