The ratings of three Computer and Personal Electronics stocks are down this week, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

This week, Xyratex (NASDAQ:XRTX) falls to a D (“sell”), worse than last week’s grade of C (“hold”). Xyratex provides modular solutions for the enterprise data storage industry and hard disk drive (HDD) capital equipment for the HDD industry. In Portfolio Grader’s specific subcategories of Margin Growth and Sales Growth, XRTX also gets F’s. While the Nasdaq has increased 2.4% over the past month, the stock price has fallen 34.2% over the past month. To get an in-depth look at XRTX, get Portfolio Grader’s complete analysis of XRTX stock.

Intevac Inc.‘s (NASDAQ:IVAC) rating falls this week to a F (“strong sell”), down from last week’s D (“sell”). Intevac designs, manufactures, and sells complex capital equipment that is primarily used to manufacture data storage products and flat panel displays. In Earnings Revisions, Equity, Cash Flow, and Margin Growth the stock gets F’s. The price of IVAC has declined 4.5% from a month prior. For more information, get Portfolio Grader’s complete analysis of IVAC stock.

The rating of Intermec (NYSE:IN) declines this week from a D to a F. Intermec is a pure Automatic Identification and Data Capture (AIDC) vendor. The stock gets F’s in Earnings Momentum, Earnings Revisions, and Equity. Cash Flow and Sales Growth also get F’s. For a full analysis of IN stock, visit Portfolio Grader.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.