Stifel lowered its rating for Intel, noting the company could face pressure as the upgrading cycle in its computer-server business peaks.

At the same time, the investment bank increased its rating on competitor Advanced Micro Devices.

"While we may be early on this, we believe the upgrade cycle may peak in 2H18," analyst Kevin Cassidy said in a note Wednesday. "Longer term, we have a positive view on Intel's strategy for transitioning to a data-centric company from PC-centric though this may take years to develop."

Cassidy lowered his rating on the Dow Jones industrial average component to hold from buy and maintained his price target of $53. Cassidy's target implies a 6 percent upside from Wednesday's close of $49.99.

The stock rose 0.8 percent on Thursday to close at $50.38.

The analyst also said Intel's advantage in the processor space has "degraded," and competitor Advanced Micro Devices was catching up. "While we understand that process technologies may not be exact comparisons, we find it increasingly difficult to see Intel's process advantage," he said.

In a separate note Wednesday, Cassidy upgraded AMD's stock to buy from hold as its valuation looks attractive.

"We believe the market has oversold the AMD shares based on alternative crypto-currency mining solutions coming to market," the analyst said. AMD chips have been widely used to mine digital currencies.

Cassidy also sees an opportunity for AMD to increase its market share in the PC space, noting the company "now has a full line-up of PC CPUs."

AMD rose 2.6 percent Thursday to $10.02, nearly 30 percent below Stifel's price target of $13 a share.