You may have heard that Dynamics CRM 2011 requires 64-bit architecture. This is true and is giving some folks some heartburn when they start to think about upgrading their CRM 4.0 deployments, many of which are still living in a 32-bit world.
There are three potential upgrade paths, as well as another alternative that I would urge you to consider. Let’s take a look.

In-Place Upgrade

An in-place upgrade is pretty straightforward: You’ve got an existing CRM 4.0 system that is running on hardware and software that is supported for CRM 2011. You fire up the setup.exe for CRM 2011 and it detects that CRM 4.0 is in place and asks if you want to proceed with an upgrade.
PROS: Straightforward, no need to lay out money for new hardware.
CONS: Risky – if the upgrade fails, you need to know how to roll back to your backups; Disruptive – while you’re upgrading, your users won’t be able to access CRM.

Upgrade Database During Install

In this scenario, you install CRM 2011 to a new 64-bit application server, and connect to a SQL server with an existing CRM 4.0 database. The 4.0 database will be upgraded during the install. This is a decent option if you’ve already got your SQL database on support hardware and SQL versions. It’s a little easier to recover from in case of failure than an in-place upgrade, since all you need to do is restore your databases.
PROS: Leverages your investment in 64-bit SQL hardware/software; once-and-done installation if you succeed.
CONS: Similar risks to the in-place upgrade though perhaps slightly less disruptive to end users.

Upgrade via Import

This is my preferred manner for upgrade. Essentially you build a new 64-bit environment for a clean install of CRM 2011 – the application servers and database servers are brand new and without remnants of CRM 4.0. After you’re satisfied with your new CRM 2011 environment, you simply restore a backup of your 4.0 database to the 2011 SQL Server, and then, using the CRM 2011 Deployment Manager, import the 4.0 org database into your new deployment. I’ve done this several times now, and it works like a charm, upgrading the org during the import process.
PROS: Nice, new, bug-free 2011 environment; opportunity to perform upgrade tests multiple times before your “go-live” upgrade; no disruption to users.
CONS: This is the most expensive scenario, requiring new hardware (or at least separate hardware) for the 2011 deployment. Also, you need to manually copy over things like supporting ISV files and applications that you may have had in place in your 4.0 environment.

Consider This

Lastly, I’d recommend that you evaluate CRM Online while considering your upgrade options. Now is a great time to take advantage of the improved functionality, affordability, and ease-of-maintenance that CRM Online provides.  If you have been managing a CRM 4.0 on-premises deployment, and want to move to the latest version of CRM, there are many good reasons to consider the cloud. C5 Insight can upgrade your database for you and then migrate your customizations and data to Microsoft’s data centers, allowing you to go back to running your business instead of running servers. Think about it!

Originally posted at my C5 Insight blog.