Google Cloud Platform cut prices again today, with Google boasting that the service is now 40 percent cheaper than any other public cloud provider's.

Google reduced prices of virtual machines by up to 30 percent and lowered the cost of all Google Compute Engine Instance types as well.

So continues the years-long price war between Amazon Web Services (AWS) and Google Cloud. Each has been willing to dig deep into its own margins rather than admitting defeat by losing customers to cheaper competition — although Google has also said that Google Cloud prices will fall in parallel with the advances provided by Moore's Law.

According to a count by Business Insider, AWS has cut its prices 44 times in the last six years, forcing Google Cloud to reduce prices several times just to keep up. In 2012, Google Cloud announced two storage price cuts, one just a day after Amazon cut its S3 storage prices by 25 percent. Last spring, Google Cloud cut prices across most major services and all regions, stealing the "low-cost provider" title from AWS.

Analysis from RBC Capital says AWS lowered prices 8 percent between October 2013 and December 2014, and Google Cloud came in just behind it at 6 percent.

While cloud providers are still lowering prices, it's not happening with the same tenacity as it was in the past. At AWS' most recent re:Invent conference, it didn't even announce a price cut, which was odd considering that had become a staple of AWS news events.

It looks like the last price reduction from AWS came late last year. The decreased prices for three different types of data transfers became effective Dec. 1.