It is mostly sufficient if you like to buy low and sell high and your investment risk horizon is beyond a quarter. Others factors such as perceived future growth rates, margins, and debt levels only color this information to a limited extent. For example, if a company grows and makes more money, then its stock price would probably go up. But the P/E ratio would remain similar. In Marvell's case, it didn't make what analysts were expecting. So share prices fell. General bull and bear market trends also play a significant role. For this year, it appears that everyone's favorite commodity, oil, will determine general market trends. If we look at Apple (AAPL), which is a very successful technology related stock over the last five years, we see a current P/E ratio of 20.
MRVL has a stock P/E ratio of about 13. LSI has a stock P/E ratio of about 105. BRCM has a stock P/E ratio of about 21. NVDA has a stock P/E ratio of about 47. QCOM has a stock P/E ratio of about 27. I would guess below 30 is a buy signal and above 35 is a sale signal.