This month, Google has advanced the Nearline Storage service first introduced in March 2015 to general availability status. Nearline Storage is the third tier for data storage — it is slower yet cheaper than the existing Durable Reduced Availability offering in Google Cloud Platform. As part of a promotion to kick off the launch of Nearline Storage, Google is offering free storage of up to 100 petabytes — that is, 100,000 terabytes — for six months for new customers who commit to transferring at least 1 PB of data within three months.

With this third tier added to Google’s catalog of cloud storage options, IT departments can minimize cloud data storage expenditures by provisioning storage based on immediate need. The same is true for users of AWS, as S3 also provides three tiers — however, there are vast differences in billing and performance between the two.

How Google Nearline compares with Amazon Glacier

The storage cost comparison between Google and Amazon is somewhat challenging to make. Pricing at Amazon depends on which facility it is stored at, and how much data is stored — for the US East facility, the standard storage tier is $0.03 GB/month and reduced redundancy is $0.024 GB/month (both of which are subject to volume discounts) and Glacier storage at $0.01 GB/month. Google’s pricing for standard storage is $0.026 GB/month, with durable reduced availability at $0.02 GB/month, and Nearline storage priced at $0.01 GB/month. Notably, Glacier has steep penalties — $0.03 per GB — for data deleted before 90 days has passed. For comparison, Nearline usage is billed as a one-month minimum.

Google’s raw storage costs undercut Amazon, but the raw storage cost is only part of the picture — Nearline and Glacier storage are both $0.01 GB/month, but API access and network egress costs add substantially to the costs. Google’s TCO calculator highlights this issue for various use cases. There are a variety of disclaimers to be had when using a vendor’s price calculator — your usage case will likely vary from the included examples, the costs of API hits are more pronounced for interactive cases (applications) than data backup, etc., though Google notes that the pricing claims (PDF) are validated by ESG Labs.

The other consideration between Nearline and Glacier is performance. They are positioned as competing products, but the delay in archive retrieval for Glacier is measured in hours, relative to the few seconds it takes for archives to be available on Nearline. Considering the delay in access, it would seem probable that Glacier is utilizing tape storage, though when that service launched in 2012, an Amazon representative told ZDNet that it does not run on tape, but instead is intended to be hardware-agnostic, using “inexpensive commodity hardware components.” However, anecdotal evidence points to Glacier running on SpectraLogic LTO5 or LTO6 tapes.

The effect of cloud on the tape storage industry

New advances in tape storage are being developed — Sony announced a tape with an areal recording density of 148 Gb/in2 in 2014, but this has not yet reached any commercially available product. IBM’s storage hardware sales are down, leading to speculation that this division will be sold off, as have other divisions of IBM have been in recent years.

The cost of tape deployments for small and medium businesses probably isn’t worth it — the volume of data needed is far too great for it to make sense financially. According to this breakdown at ZDNet, the array itself (minus tapes) pushes $450,000, and the yearly storage prices of Amazon or Google make this less than a sensible solution for SMB data archival volumes.

There are likely edge cases where tape makes sense, but for most businesses, the physical cost of the hardware, combined with the power needed to run it (granted, this is less than disk drives) puts it out of the realm of feasibility for many organizations. However, with LTO-7 around the corner, the existing calculations will need to be re-assessed.

What’s your view?

Does your organization still deploy tape drives? Is the free storage offer from Google compelling enough to warrant migrating away from AWS? Share your storage strategies.

Note: TechRepublic and ZDNet are CBS Interactive properties.