Sleep Number P-6 VS. I-8 – Which Model Is Best?

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Both the P-6 and the I-8 mattresses from Sleep Number offer 3” of PlushFit foam and built-in features to keep people sleeping cool and asleep through the night. There are subtle details in each mattress that set them apart from each other.

So, which one is right for you? Check out our handy guide that breaks down the features in each mattress.

Key Similarities

  • Both offer 3” of proprietary PlushFit foam – supportive foam is designed exclusively for Sleep Number to naturally conform to the body’s curves
  • A variety of standard sizes – including FlexTop
  • Individual or dual air chamber options with DualAir™ adjustability

Both come with this optional feature:
FlexFit™ Adjustable Bases

Key Differences


  • 12” mattress profile
  • Traditional plush-style design mattress top
  • Mattress fabric is made with a breathable rayon/polyester knit blend with moisture-wicking technology for a cool sleep surface
  • 5 zones specifically designed to contour to the head/neck, shoulders, lower back, hips, and feet
  • $2,599.99 for a Queen



  • 13” mattress profile
  • Duvet pillow top that includes 2” of hypersoft quilting foam for a plush surface and Outlast temperature balancing technology to minimize temperature swings
  • 1” foam base pad underneath the air chamber(s)
  • 7 zones specifically designed to contour to the head, shoulders, lower back, hips, knees, lower legs, and feet
  • Mattress fabric is made with a polyester/polypropylene blend fabric that is designed to be soft and breathable
  • Sleep IQ Technology included
  • $3,499.98 for a Queen

What I Found From Several Live Chat Sessions

After speaking with Sleep Number Customer Service representatives, I learned about a few extra details and clarifications that may help people decide between a P-6 or an I-8 mattress.

  • Mattress Top and Firmness: Both mattresses offer unique tops which end up making a slight difference in firmness between them. The P-6 has a more traditional soft knit top, while the I-8 has a duvet pillow top that includes 2” of Hypersoft Quilting Foam. Customer Service told me that the I-8 is slightly more plush than the P-6, which will make the P-6 a firmer mattress (but only by a little).
  • Cooling Technology: The P-6 and the I-8 both feature fabric that is intended to help keep people cool at night. The P-6 has moisture wicking technology in the fabric of the mattress but the I-8 has Outlast technology built into the mattress top. Outlast technology is designed to pull moisture away from the body and redistribute it throughout the night.

Which Should Pick?

P-6 if…

  • People Want A Firmer Mattress. Customer Service at Sleep Number told me that between the P-6 and the I-8 mattress, the I-8 is softer (and also more popular). This is most likely because of the unique mattress top in the I-8 that comes with quilting foam sewn in. Those who are looking for something firmer may want to go with the P-6.
  • People Want To Spend Less. There is a $900 price difference between Queen size P-6 and I-8 mattresses. Going with the P-6 frees up some funds to purchase accessories like Sleep IQ Technology, a FlexFit Adjustable Base or other mattress pads and sheets that are customized for Sleep Number beds.

Read our full Sleep Number P-6 review

I-8 if…

  • People Want A Softer Mattress Top. The I-8 has a super comfortable mattress top. It’s got a woven Duvet pillow-top that includes 2” of Hypersoft Quilting Foam for a plush surface, according to Customer Service. They specifically told me that this makes it slightly softer than the P-6 and is also the more popular choice.
  • People Want Full Body Pressure Relief. The 3” comfort foam in the I-8 is designed to relieve pressure in 7 areas of the body and the P-6 is designed to relieve pressure in only 5 areas. The I-8 adds body contouring to the knees and lower legs and the P-6 design does not focus on those areas.
  • People Want Sleep IQ Technology Included. Sleep IQ Technology is inserted into the mattress and used to track someone’s sleep and help them find their ideal Sleep Number Setting. This is already included when they purchase an I-8 mattress. They would need to pay extra for it (roughly $199) to add it in if they go with the P-6.

Read our full Sleep Number I-8 review

Both if…

  • Someone Is A Hot Sleeper. Both mattresses include cooling technology. The P-6 has moisture-wicking fabric in the mattress knit but the I-8 has the Outlast technology, designed to pull moisture away from the sleeper at night and redistribute it throughout the night.

For those that are interested in learning more about the Sleep Number brand its various models, they can learn more information here.

Personal Opinion

There is a $900 price between a Queen P-6 mattress ($2,599.99) and a Queen I-8 mattress ($3,499.98). Here is what people get with the I-8 that they can’t get with the P-6:

  • 1” foam base pad
  • Outlast Technology in mattress surface for temperature regulation
  • Plusher mattress top with quilting foam sewn in
  • Sleep IQ Technology

Customer Service did tell me that the I-8 mattress was more popular than the P-6 simply because it is softer – thanks to its more luxurious mattress top with fabric that will control any temperature swings.

In my opinion, the P-6 is very close to the best selling P-5 model and offers a good amount cushion and its own moisture-wicking fabric that I would save the money and go with the P-6 over the I-8.

As someone who prefers a firmer mattress and would prefer to control temperature with my own mattress topper or mattress protector, I would save the money and choose the P-6 over the I-8 mattress.

Read our full Sleep Number review

Gravatar for Katie Golde

Katie Golde

Katie manages the day to day operations of the Mattress Clarity news site and reviews sleep products in addition to writing and editing sleep news. She hails from Austin, where she lives with her growing family. She is a Certified Sleep Science Coach and has a master’s degree in Journalism from Northwestern University and has a background in health and science content. Her work can be found in print and online publications like Discover Magazine, USA Today and The Huffington Post.